Post-bonded grooved elastic materials

ABSTRACT

An elastic nonwoven laminate that contains an elastic film laminated to one or more nonwoven facings is provided. The nonwoven facing contains a conventional polyolefin and can also contain a polyolefin-based plastomer. The laminate is activated by grooving to decouple the nonwoven facing from the elastic film. To reduce fiber-pull out that can result due to activation by grooving, the laminate can be post-bonded at room or elevated temperatures and a specific range of pressures to compact the fibers of the facing and minimize fiber pull-out/fuzziness while not sacrificing the softness, elasticity, and feel of the laminate.

BACKGROUND OF THE INVENTION

Elastic laminates (e.g., multilayered materials having elasticproperties) are used in a wide variety of absorbent articles. An elasticlaminate generally has the ability to be stretched, and once thestretching force is removed, the material can retract and recover. Inmany applications, it is also desirable that the elastic laminates aresoft and not sticky or tacky, as such laminates are often in contactwith a user's skin. Moreover, in some instances, such elastic laminatesare intended to be used more than one time. For example, the elasticlaminates used for diaper ears that contain fastening mechanisms tosecure the waistband of a diaper around a wearer may be unfastened andrefastened multiple times to adjust the fit of the diaper or to checkfor insults in the diaper. Meanwhile, other elastic laminates can beincluded in an absorbent article in predetermined locations to optimizefit, make the article more comfortable to wear through improved fit,and/or improve the ability of the article to absorb liquids whilepreventing leakage through improved containment structures andgasketing.

Regardless of the particular absorbent article end use, elasticlaminates can be made using various methods. In one method, a nonelasticcomponent is joined to an elastic component while the elastic componentis in a stretched condition so that when the elastic component isrelaxed, the nonelastic component gathers between the locations where itis bonded to the elastic component. The resulting elastic laminatematerial is stretchable to the extent that the nonelastic componentgathered between the bond locations allows the elastic component toelongate. It has been found that stretch bonded laminate materials tendto be fairly costly to manufacture and their inclusion in a productnecessarily increases the cost of the end product to the consumer. Itwould therefore be desirable to provide efficient method for formingelastic materials having the desired level of softness and at a lowercost.

It is also known to laminate (or bond) a necked (neckable) material toan elastic sheet to produce a neck bonded laminate as described in U.S.Pat. No. 5,226,992 to Morman, et al. This process involves an elasticmember being bonded to a non-elastic member while only the non-elasticmember is extended in one direction (usually the machine direction) andnecked in the transverse direction (usually the cross-machine direction)so as to reduce its dimension in the direction orthogonal to theextension. However, the production of such laminates is often notefficient, and the desired elastic properties may not be achieved, suchas 200% elongation in the cross-machine direction, because elongation inthe cross-machine direction is limited due to necking.

Another method of forming elastic laminates involves extrusion castingan elastic film onto a nonwoven facing or casting a film and adhesivelybonding the film to at least one nonwoven facing. Then, the laminatescan be subsequently incrementally stretched, such as by grooving, toprovide machine direction or cross-machine direction stretch materialsdepending on the direction of the grooving. For example, machinedirection grooving of the laminates allows cross-machine directionstretch by decoupling the facings from the elastic and cross-machinegrooving of the laminates allows for machine direction stretch. However,in order to groove an elastic material to decouple the nonwoven facingfrom the elastic, the facing has often been based on a bonded carded webbecause the short length of the bonded carded web fibers and thedecreased bonding area allows for the nonwoven facing to be grooved orstriated while the elastic film remains continuous and undamaged.However, forming bonded carded webs and then grooving such webs is anexpensive and time consuming, inefficient process requiring multiplesteps. Further, the use of short fibers in the bonded carded webincreases the amount of fiber pull out, which is not always desirabledepending on the end-use application. On the other hand, it has beenobserved that the use of other nonwoven facings besides bonded cardedwebs, such as spunbond facings based on polypropylene with longer fibersand a larger percentage bond area cannot be grooved easily to provideelastic laminates that stretch and recover because of the materials usedand the amount of post bonding, which also limits the softness of suchmaterials compared to, for instance, polyethylene-based facings, whichare also more cost effective. Further, grooving tends to loosen thefibers in such facings, which leads to difficulty in hook engagement andpotentially increased fiber pull out, which can create challenges whenutilizing these facings in absorbent article fastening systems. Also,the use of meltblown facings, although they may be easily grooved, isnot ideal because of the loosely configured or fuzzy appearance and lackof integrity of the meltblown facings, as well as the potentialdisadvantages associated with fiber pull out in absorbent articleapplications.

As such, a need exists for a laminate utilizing meltblown or spunbondfacings with sufficient elasticity, groovability, comfort, and softnessthat can also be used in absorbent article applications where minimalfiber pullout and durability are desired.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the present invention, a method offorming an elastic laminate having a machine direction and a crossmachine direction is disclosed. The method includes joining an elasticfilm with a nonwoven facing to form a laminate, where the nonwovenfacing comprises a first polyolefin, the nonwoven facing is meltblown orspunbond, the elastic film is in an unstretched state. In addition, themethod includes feeding the laminate through a first nip formed by afirst roll and a second roll, where at least one of the rolls definesgrooves, and where the laminate is fed in between the two rolls withsufficient nip pressure to groove the nonwoven facing such that thegrooving decouples the nonwoven facing from the elastic film in themachine direction or the cross-machine direction. Moreover, the methodincludes feeding the laminate through a second nip formed by bond rollsat a bonding station to bond least an outer surface of the nonwovenfacing, where the bonding occurs at a temperature ranging from about 65°F. to about 300° F. and at a pressure ranging from about 5 psi to about100 psi.

In one embodiment, the first polyolefin includes polyethylene,polypropylene, or a combination thereof. In another embodiment, thelaminate further includes a second polyolefin, where the secondpolyolefin comprises an elastomeric semi-crystalline polyolefin. Theelastomeric semi-crystalline polyolefin can be an ethylene/α-olefincopolymer, propylene/α-olefin copolymer, or a combination thereof.

In yet another embodiment, the at least one of the bond rolls ispatterned. The at least one bond roll can be patterned with raisedbonding elements. Further, the at least one bond roll is patterned witha wire weave pattern. In addition, the pattern can cover from 10% toabout 60% of the total surface area of the nonwoven facing.

In still another embodiment, the elastic film can be disposed between afirst nonwoven facing and a second nonwoven facing. In anotherembodiment, the elastic nonwoven laminate can be grooved in the machinedirection to provide cross-machine direction stretch to the elasticnonwoven laminate.

In an additional embodiment, a tab attached to the nonwoven facing canbe elongated from about 50% to about 200% before becoming disengagedfrom the nonwoven facing. In one more embodiment, the elastic nonwovenlaminate formed by the method of the present disclosure can have apercent elongation of at least about 200% in the cross machinedirection.

In another embodiment, the elastic nonwoven laminate formed by themethod of the present disclosure can include an elastic film, where theelastic film includes a core layer disposed between two skin layers,where the core layer is an elastic layer that includes a styrenic blockcopolymer, an ethylene/α-olefin copolymer, a propylene/α-olefincopolymer, or a combination thereof. In an additional embodiment, theelastic film can be disposed between a first nonwoven meltblown facingand a second nonwoven meltblown facing, where the elastic film comprisesa core layer disposed between two skin layers, and where the core layeris a strength layer and the two skin layers are elastic layers.

In accordance with another embodiment of the present invention, anelastic laminate having a machine direction and a cross machinedirection is disclosed. The elastic nonwoven laminate includes anunstretched elastic film positioned adjacent a nonwoven facing. Thenonwoven facing includes a first polyolefin, and the nonwoven facing ismeltblown or spunbond. Further, the nonwoven facing is grooved in themachine direction or cross-machine direction, and at least an outersurface of the nonwoven facing is bonded. In addition, the elasticnonwoven laminate has a percent elongation of at least about 200% in thecross machine direction.

In one particular embodiment, the first polyolefin includespolyethylene, polypropylene, or a combination thereof. In still anotherembodiment, the nonwoven facing further includes a second polyolefin,wherein the second polyolefin comprises an elastomeric semi-crystallinepolyolefin. The elastomeric semi-crystalline polyolefin can be anethylene/α-olefin copolymer, propylene/α-olefin copolymer, or acombination thereof. In one embodiment, the first polyolefin can bepresent in an amount ranging from about 50 wt. % to about 99 wt. % andthe second polyolefin can be present in an amount ranging from about 0.5wt. % to about 60 wt. %, based on the total weight of the nonwovenfacing.

In one more embodiment, the outer surface of the nonwoven facing can bebonded in a pattern, such as a wire weave pattern.

In yet another embodiment, the elastic film can be disposed between afirst nonwoven facing and a second nonwoven facing.

In still another embodiment, the elastic film can include a core layerdisposed between two skin layers, where the core layer is an elasticlayer that includes a styrenic block copolymer, an ethylene/α-olefincopolymer, a propylene/α-olefin copolymer, or a combination thereof.

In an additional embodiment, the elastic film can be disposed between afirst nonwoven meltblown facing and a second nonwoven meltblown facing,where the elastic film includes a core layer disposed between two skinlayers, where the core layer is a strength layer, and where the two skinlayers are elastic layers.

In one more embodiment, a tab attached to the nonwoven facing can beelongated from about 50% to about 200% before becoming disengaged fromthe nonwoven facing. Further, the elastic nonwoven laminate can have apercent elongation of at least about 200% in the cross-machinedirection.

In yet another embodiment, the elastic nonwoven laminate can further afrangible layer. In an additional embodiment, the present inventioncontemplates an absorbent article comprising the elastic nonwovenlaminate as discussed above. Further, the absorbent article can includean ear or fastening component that includes the elastic nonwovenlaminate as described above. In another embodiment, a waist band, legband, or both can include the elastic nonwoven laminate as describedabove.

Other features and aspects of the present invention are described inmore detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth more particularly in the remainder of the specification, whichmakes reference to the appended figures in which:

FIG. 1 schematically illustrates a method for forming a compositeaccording to one embodiment of the present invention;

FIG. 2 is a perspective view of grooved rolls that may be used in oneembodiment of the present invention;

FIG. 3 is a cross-sectional view showing the engagement between two ofthe grooved rolls of FIG. 2;

FIG. 4 is a schematic side view of an apparatus for making a patternunbonded (PUB) nonwoven material in accordance with one embodiment ofthe present invention;

FIG. 5 is a perspective view of a patterned roll that can be used inaccordance with the apparatus of FIG. 4;

FIG. 6 is a top view of a pattern unbonded nonwoven material formed inaccordance with one embodiment of the present invention;

FIG. 7 illustrates one embodiment of an “S-weave” bonding pattern thatmay be used in accordance with the present invention;

FIG. 8 illustrates one embodiment of a “rib-knit” bonding pattern thatmay be used in accordance with the present invention;

FIG. 9 illustrates one embodiment of a “wire-weave” bonding pattern thatmay be used in accordance with the present invention;

FIG. 10 is a top view of an absorbent article that may be formed inaccordance with one embodiment of the present invention;

FIG. 11 is a photograph of a nonwoven facing formed in accordance withone embodiment of the present invention after post-bonding and after 70%elongation; and

FIG. 12 is a photograph of a nonwoven facing formed in accordance withone embodiment of the present invention without post-bonding and after70% elongation.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the invention.

DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS Definitions

As used herein, the terms “machine direction” or “MD” generally refersto the direction in which a material is produced. The term“cross-machine direction” or “CD” refers to the direction perpendicularto the machine direction.

As used herein the term “nonwoven web” generally refers to a web havinga structure of individual fibers or threads which are interlaid, but notin an identifiable manner as in a knitted fabric. Examples of suitablenonwoven fabrics or webs include, but are not limited to, meltblownwebs, spunbond webs, bonded carded webs, airlaid webs, coform webs,hydraulically entangled webs, and so forth.

As used herein, the term “meltblown web” generally refers to a nonwovenweb that is formed by a process in which a molten thermoplastic materialis extruded through a plurality of fine, usually circular, diecapillaries as molten fibers into converging high velocity gas (e.g.air) streams that attenuate the fibers of molten thermoplastic materialto reduce their diameter, which may be to microfiber diameter.Thereafter, the meltblown fibers are carried by the high velocity gasstream and are deposited on a collecting surface to form a web ofrandomly dispersed meltblown fibers. Such a process is disclosed, forexample, in U.S. Pat. No. 3,849,241 to Butin, et al., which isincorporated herein in its entirety by reference thereto for allpurposes. Generally speaking, meltblown fibers may be microfibers thatare substantially continuous or discontinuous, generally smaller than 10microns in diameter, and generally tacky when deposited onto acollecting surface.

As used herein, the term “spunbond web” generally refers to a webcontaining small diameter substantially continuous fibers. The fibersare formed by extruding a molten thermoplastic material from a pluralityof fine, usually circular, capillaries of a spinnerette with thediameter of the extruded fibers then being rapidly reduced as by, forexample, eductive drawing and/or other well-known spunbondingmechanisms. The production of spunbond webs is described andillustrated, for example, in U.S. Pat. No. 3,338,992 to Kinney, U.S.Pat. No. 3,341,394 to Kinney, U.S. Pat. No. 3,502,538 to Levy, U.S. Pat.No. 3,502,763 to Hartman, U.S. Pat. No. 3,542,615 to Dobo, et al., U.S.Pat. No. 3,692,618 to Dorschner, et al., U.S. Pat. No. 3,802,817 toMatsuki, et al., U.S. Pat. No. 4,340,563 to Appel, et al., and U.S. Pat.No. 5,382,400 to Pike et al., which are incorporated herein in theirentirety by reference thereto for all purposes. Spunbond fibers aregenerally not tacky when they are deposited onto a collecting surface.As such, the fibers may be bonded together after deposition onto acollecting surface in order to integrate the fibers. Spunbond fibers maysometimes have diameters less than about 40 microns, and are oftenbetween about 5 to about 20 microns.

As used herein, the term “bonded carded web” refers to webs made fromstaple fibers which are sent through a combing or carding unit, whichbreaks apart and aligns the staple fibers in the machine direction toform a generally machine direction-oriented fibrous nonwoven web. Suchfibers are usually purchased in bales which are placed in a picker orfiberizer which separates the fibers prior to the carding unit. Once theweb is formed, it is then bonded by one or more of several known bondingmethods.

As used herein the terms “extensible” or “extensibility” generallyrefers to a material that stretches or extends in the direction of anapplied force by at least about 25%, in some embodiments about 50%, andin some embodiments, at least about 75% of its relaxed length or width.An extensible material does not necessarily have recovery properties.For example, an elastomeric material is an extensible material havingrecovery properties, while a necked meltblown web may be extensible, butnot have recovery properties, and thus, is considered an extensible,non-elastic material.

As used herein, the term “elastomeric” and “elastic” and refers to amaterial that, upon application of a stretching force, is stretchable inat least one direction (such as the CD direction), and which uponrelease of the stretching force, contracts/returns to approximately itsoriginal dimension. For example, a stretched material may have astretched length that is at least 50% greater than its relaxedunstretched length, and which will recover to within at least 50% of itsstretched length upon release of the stretching force. A hypotheticalexample would be a one (1) inch sample of a material that is stretchableto at least 1.50 inches and which, upon release of the stretching force,will recover to a length of not more than 1.25 inches. Desirably, thematerial contracts or recovers at least 50%, and even more desirably, atleast 80% of the stretched length.

As used herein, the term “necked material” refers to any material whichhas been narrowed in at least one dimension by application of atensioning force.

As used herein, the term “thermal point bonding” generally refers to aprocess performed, for example, by passing a material between apatterned roll (e.g., calender roll) and another roll (e.g., anvilroll), which may or may not be patterned. One or both of the rolls aretypically heated.

As used herein, the term “ultrasonic bonding” generally refers to aprocess performed, for example, by passing a material between a sonichorn and a patterned roll (e.g., anvil roll). For instance, ultrasonicbonding through the use of a stationary horn and a rotating patternedanvil roll is described in U.S. Pat. No. 3,844,869 to Rust Jr., U.S.Pat. No. 3,939,033 to Grgach, et al., and U.S. Pat. No. 4,259,399 toHill, which are incorporated herein in their entirety by referencethereto for all purposes. Moreover, ultrasonic bonding through the useof a rotary horn with a rotating patterned anvil roll is described inU.S. Pat. No. 5,096,532 to Neuwirth et al., U.S. Pat. No. 5,110,403 toEhlert, and U.S. Pat. No. 5,817,199 to Brennecke, et al., which areincorporated herein in their entirety by reference thereto for allpurposes. Of course, any other ultrasonic bonding technique may also beused in the present invention.

DETAILED DESCRIPTION

Reference now will be made in detail to various embodiments of theinvention, one or more examples of which are set forth below. Eachexample is provided by way of explanation, not limitation of theinvention. In fact, it will be apparent to those skilled in the art thatvarious modifications and variations may be made in the presentinvention without departing from the scope or spirit of the invention.For instance, features illustrated or described as part of oneembodiment, may be used on another embodiment to yield a still furtherembodiment. Thus, it is intended that the present invention cover suchmodifications and variations.

Generally speaking, the present invention is directed to an elasticnonwoven laminate that contains an elastic film laminated to one or morenonwoven facings. The nonwoven facing can include a conventionalpolyolefin which can, in some embodiments, be combined with apolyolefin-based plastomer. Further, the nonwoven facing can be spunbondor meltblown. The laminate can be activated by grooving and then can bepost-bonded. By activation, it is meant that the laminate's elasticity,attributed to the elastic film, is unlocked, such as by breakingportions of the nonwoven facing. The present inventors have found thatby selectively controlling certain parameters of the lamination process,such as film content, nonwoven facing content, bonding pattern, bondingconditions, etc., a desired level of compaction to prevent the fiberpull-out typically seen in groove-activated spunbond or meltblown webscan be achieved without sacrificing the elasticity, softness, loftiness,hand feel, and/or aesthetic appeal of the resulting laminate. Thus, aspunbond or meltblown elastic nonwoven laminate can be produced that canbe reusable, such as in fastening/unfastening applications, due to thereduced occurrence of fiber pull-out, which also minimizes the“fuzziness” of the laminate despite utilizing grooving to activate thelaminates instead of other activation methods, such as heat activation.As such, the elastic nonwoven laminate of the present invention can beused instead of bonded carded web-based elastic laminates. Further,Applicants have found that an improved bond can be formed between thenonwoven facings and the elastic film of the elastic nonwoven laminatesof the present invention compared to bonded carded web elasticlaminates, which are more loosely configured or fuzzier.

In this regard, various embodiments of the present invention will now bedescribed in more detail.

I. Elastic Film

The elastic film component of the elastic nonwoven laminate of thepresent invention is formed from one or more layers of polymers that aremelt-processable, i.e., thermoplastic. For instance, in one particularembodiment, the elastic film can be a monolayer film. If the film is amonolayer, any of the polymers discussed below in reference to the corelayer or skin layers is contemplated by the present invention. In otherembodiments, the elastic film can include two, three, four, five, six,or seven layers. For example, a three-layer film that comprises a corelayer sandwiched between two skin layers is contemplated. However, it isto be understood that any number of layers can be present, where the oneor more layers are formed from the same or different materials. Variousconfigurations for the arrangement of the elastic film in conjunctionwith the nonwoven facing are discussed below in section III.

a. Core Layer

The core layer of the elastic film of the elastic nonwoven laminate ofthe present invention can provide the laminate with the desiredelasticity. Any of a variety of thermoplastic elastomeric or plastomericpolymers may generally be employed in the core layer of the elastic filmof the elastic nonwoven laminate of the present invention. Such polymersinclude elastomeric polyesters, elastomeric polyurethanes, elastomericpolyamides, elastomeric copolymers, elastomeric polyolefins, and soforth. In one embodiment, for instance, a substantially amorphous blockcopolymer may be employed that contains blocks of a monoalkenyl areneand a saturated conjugated diene. Such block copolymers are particularlyuseful in the present invention due to their high degree of elasticity.

The monoalkenyl arene block(s) may include styrene and its analogues andhomologues, such as o-methyl styrene; p-methyl styrene; p-tert-butylstyrene; 1,3 dimethyl styrene p-methyl styrene; etc., as well as othermonoalkenyl polycyclic aromatic compounds, such as vinyl naphthalene;vinyl anthrycene; and so forth. Preferred monoalkenyl arenes are styreneand p-methyl styrene. The conjugated diene block(s) may includehomopolymers of conjugated diene monomers, copolymers of two or moreconjugated dienes, and copolymers of one or more of the dienes withanother monomer in which the blocks are predominantly conjugated dieneunits. Preferably, the conjugated dienes contain from 4 to 8 carbonatoms, such as 1,3 butadiene (butadiene); 2-methyl-1,3 butadiene;isoprene; 2,3 dimethyl-1,3 butadiene; 1,3 pentadiene (piperylene); 1,3hexadiene; and so forth. The amount of monoalkenyl arene (e.g.,polystyrene) blocks may vary, but typically constitute from about 8 wt.% to about 55 wt. %, in some embodiments from about 10 wt. % to about 35wt. %, and in some embodiments from about 15 wt. % to about 25 wt. % ofthe copolymer. Suitable block copolymers may contain monoalkenyl areneendblocks having a number average molecular weight from about 5,000 toabout 35,000 and saturated conjugated diene midblocks having a numberaverage molecular weight from about 20,000 to about 170,000. The totalnumber average molecular weight of the block polymer may be from about30,000 to about 250,000.

Particularly suitable thermoplastic elastomeric copolymers are availablefrom Kraton Polymers LLC of Houston, Tex. under the trade name KRATON®.KRATON® polymers include styrene-diene block copolymers, such asstyrene-butadiene, styrene-isoprene, styrene-butadiene-styrene,styrene-isoprene-styrene, and styrene-isoprene/butadiene-styrene.KRATON® polymers also include styrene-olefin block copolymers formed byselective hydrogenation of styrene-diene block copolymers. Examples ofsuch styrene-olefin block copolymers includestyrene-(ethylene-butylene), styrene-(ethylene-propylene),styrene-(ethylene-butylene)-styrene,styrene-(ethylene-propylene)-styrene,styrene-(ethylene-butylene)-styrene-(ethylene-butylene),styrene-(ethylene-propylene)-styrene-(ethylene-propylene), andstyrene-ethylene-(ethylene-propylene)-styrene. These styrenic blockcopolymers may have a linear, radial or star-shaped molecularconfiguration. Specific KRATON™ block copolymers include those soldunder the brand names D 1102, D 1171, G 1652, G 1657, G 1730, MD 6673,and MD 6973. Various suitable styrenic block copolymers are described inU.S. Pat. No. 4,323,534 to DesMarais, U.S. Pat. No. 4,663,220 toWisneski, et al., U.S. Pat. No. 4,834,738 to Kielpikowski et al., U.S.Pat. No. 5,093,422 to Himes, and U.S. Pat. No. 5,304,599 to Himes, aswell as U.S. Patent Application Publication Nos. 2012/0172214 to Thomasand 2012/0172516 to Wright, et al., which are hereby incorporated intheir entirety by reference thereto for all purposes. Other commerciallyavailable block copolymers include the S-EP-S elastomeric copolymersavailable from Kuraray Company, Ltd. of Okayama. Japan, under the tradedesignation SEPTON™. Still other suitable copolymers include S-I-S andS-B-S elastomeric copolymers, which are available from Dexco Polymers ofHouston, Tex. or TSRC Company of Taiwan under the trade designationVECTOR™. Also suitable are polymers composed of an A-B-A-B tetrablockcopolymer, such as discussed in U.S. Pat. No. 5,332,613 to Taylor, etal., which is incorporated herein in its entirety by reference theretofor all purposes. An example of such a tetrablock copolymer is astyrene-poly(ethylene-propylene)-styrene-poly(ethylene-propylene)(“S-EP-S-EP”) block copolymer.

In one particular embodiment, the core layer of the elastic film of thepresent invention can include multiple styrenic block copolymers. Forinstance, the elastic film can include a styrene-butadiene-styrenecopolymer and a styrene-isoprene/butadiene-styrene copolymer. Thestyrene-butadiene-styrene copolymer can be present in an amount rangingfrom about 5 wt. % to about 60 wt. %, such as from about 10 wt. % toabout 55 wt. %, such as from about 15 wt. % to about 50 wt. % based onthe total weight of the core layer. Meanwhile, thestyrene-isoprene/butadiene-styrene copolymer can be present in an amountranging from about 30 wt. % to about 75 wt. %, such as from about 35 wt.% to about 70 wt. %, such as from about 40 wt. % to about 65 wt. % basedon the total weight of the core layer.

Of course, other thermoplastic elastomeric polymers may also be used toform the film, either alone or in conjunction with the block copolymers.Semi-crystalline polyolefins, for example, may be employed that have orare capable of exhibiting a substantially regular structure. Exemplarysemi-crystalline polyolefins include polyethylene, polypropylene, blendsand copolymers thereof. In one particular embodiment, a polyethylene isemployed that is a copolymer of ethylene and an α-olefin, such as aC₃-C₂₀ α-olefin or C₃-C₁₂ α-olefin. Suitable α-olefins may be linear orbranched (e.g., one or more C₁-C₃ alkyl branches, or an aryl group).Specific examples include 1-butene; 3-methyl-1-butene;3,3-dimethyl-1-butene; 1-pentene; 1-pentene with one or more methyl,ethyl or propyl substituents; 1-hexene with one or more methyl, ethyl orpropyl substituents; 1-heptene with one or more methyl, ethyl or propylsubstituents; 1-octene with one or more methyl, ethyl or propylsubstituents; 1-nonene with one or more methyl, ethyl or propylsubstituents; ethyl, methyl or dimethyl-substituted 1-decene;1-dodecene; and styrene. Particularly desired α-olefin comonomers are1-butene, 1-hexene and 1-octene. The ethylene content of such copolymersmay be from about 60 mole % to about 99 mole %, in some embodiments fromabout 80 mole % to about 98.5 mole %, and in some embodiments, fromabout 87 mole % to about 97.5 mole %. The α-olefin content may likewiserange from about 1 mole % to about 40 mole %, in some embodiments fromabout 1.5 mole % to about 15 mole %, and in some embodiments, from about2.5 mole % to about 13 mole %.

Particularly suitable polyethylene copolymers are those that are“linear” or “substantially linear.” The term “substantially linear”means that, in addition to the short chain branches attributable tocomonomer incorporation, the ethylene polymer also contains long chainbranches in the polymer backbone. “Long chain branching” refers to achain length of at least 6 carbons. Each long chain branch may have thesame comonomer distribution as the polymer backbone and be as long asthe polymer backbone to which it is attached. Preferred substantiallylinear polymers are substituted with from 0.01 long chain branch per1000 carbons to 1 long chain branch per 1000 carbons, and in someembodiments, from 0.05 long chain branch per 1000 carbons to 1 longchain branch per 1000 carbons. In contrast to the term “substantiallylinear”, the term “linear” means that the polymer lacks measurable ordemonstrable long chain branches. That is, the polymer is substitutedwith an average of less than 0.01 long chain branch per 1000 carbons.

The density of a linear ethylene/α-olefin copolymer is a function ofboth the length and amount of the α-olefin. That is, the greater thelength of the α-olefin and the greater the amount of α-olefin present,the lower the density of the copolymer. Although not necessarilyrequired, linear polyethylene “plastomers” are particularly desirable inthat the content of α-olefin short chain branching content is such thatthe ethylene copolymer exhibits both plastic and elastomericcharacteristics—i.e., a “plastomer.” Because polymerization withα-olefin comonomers decreases crystallinity and density, the resultingplastomer normally has a density lower than that of a polyethylenethermoplastic polymer (e.g., LLDPE), which typically has a density(specific gravity) of from about 0.90 grams per cubic centimeter (g/cm³)to about 0.94 g/cm³, but approaching and/or overlapping that of anelastomer, which typically has a density of from about 0.85 g/cm³ toabout 0.90 g/cm³, preferably from 0.86 to 0.89. For example, the densityof the polyethylene plastomer may be 0.91 g/cm³ or less, in someembodiments from about 0.85 g/cm³ to about 0.90 g/cm³, in someembodiments, from 0.85 g/cm³ to 0.88 g/cm³, and in some embodiments,from 0.85 g/cm³ to 0.87 g/cm³. Despite having a density similar toelastomers, plastomers generally exhibit a higher degree ofcrystallinity, are relatively non-tacky, and may be formed into pelletsthat are non-adhesive-like and relatively free flowing.

Preferred polyethylenes for use in the present invention areethylene-based copolymer plastomers available under the designationEXACT™ from ExxonMobil Chemical Company of Houston, Tex. Other suitablepolyethylene plastomers are available under the designation ENGAGE™ andAFFINITY™ from Dow Chemical Company of Midland, Mich. An additionalsuitable polyethylene-based plastomer is an olefin block copolymeravailable from Dow Chemical Company of Midland, Mich. under the tradedesignation INFUSE™, which is an elastomeric copolymer of polyethylene.Still other suitable ethylene polymers are low density polyethylenes(LDPE), linear low density polyethylenes (LLDPE) or ultralow lineardensity polyethylenes (ULDPE), such as those available from The DowChemical Company under the designations ASPUN™ (LLDPE), DOWLEX™ (LLDPE)and ATTANET™ (ULDPE). Other suitable ethylene polymers are described inU.S. Pat. No. 4,937,299 to Ewen, et al., U.S. Pat. No. 5,218,071 toTsutsui et al., U.S. Pat. No. 5,272,236 to Lai, et al., and U.S. Pat.No. 5,278,272 to Lai, et al., which are incorporated herein in theirentirety by reference thereto for all purposes.

Of course, the present invention is by no means limited to the use ofethylene polymers. For instance, propylene plastomers may also besuitable for use in the film. Suitable plastomeric propylene polymersmay include, for instance, copolymers or terpolymers of propylene,copolymers of propylene with an α-olefin (e.g., C₃-C₂₀), such asethylene, 1-butene, 2-butene, the various pentene isomers, 1-hexene,1-octene, 1-nonene, 1-decene, 1-unidecene, 1-dodecene,4-methyl-1-pentene, 4-methyl-1-hexene, 5-methyl-1-hexene,vinylcyclohexene, styrene, etc. The comonomer content of the propylenepolymer may be about 35 wt. % or less, in some embodiments from about 1wt. % to about 20 wt. %, and in some embodiments, from about 2 wt. % toabout 10 wt. %. Preferably, the density of the polypropylene (e.g.,propylene/α-olefin copolymer) may be 0.91 g/cm³ or less, in someembodiments, from 0.85 g/cm³ to 0.88 g/cm³, and in some embodiments,from 0.85 g/cm³ to 0.87 g/cm³. Suitable propylene polymers arecommercially available under the designations VISTAMAXX™ (e.g., 6102), apropylene-based elastomer from ExxonMobil Chemical Co. of Houston, Tex.;FINA™ (e.g., 8573) from Atofina Chemicals of Feluy, Belgium; TAFMER™available from Mitsui Petrochemical Industries; and VERSIFY™ availablefrom Dow Chemical Co. of Midland, Mich. Other examples of suitablepropylene polymers are described in U.S. Pat. No. 5,539,056 to Yang, etal., U.S. Pat. No. 5,596,052 to Resconi, et al., and U.S. Pat. No.6,500,563 to Datta, et al., which are incorporated herein in theirentirety by reference thereto for all purposes.

Any of a variety of known techniques may generally be employed to formthe semi-crystalline polyolefins. For instance, olefin polymers may beformed using a free radical or a coordination catalyst (e.g.,Ziegler-Natta). Preferably, the olefin polymer is formed from asingle-site coordination catalyst, such as a metallocene catalyst. Sucha catalyst system produces ethylene copolymers in which the comonomer israndomly distributed within a molecular chain and uniformly distributedacross the different molecular weight fractions. Metallocene-catalyzedpolyolefins are described, for instance, in U.S. Pat. No. 5,272,236 toLai et al., U.S. Pat. No. 5,322,728 to Davis et at, U.S. Pat. No.5,472,775 to Objjeski et al., U.S. Pat. No. 5,571,619 to McAlpin et al.,and U.S. Pat. No. 6,090,325 to Wheat, et al., which are incorporatedherein in their entirety by reference thereto for all purposes. Examplesof metallocene catalysts include bis(n-butylcyclopentadienyl)titaniumdichloride, bis(n-butylcyclopentadienyl)zirconium dichloride,bis(cyclopentadienyl)scandium chloride, bis(indenyl)zirconiumdichloride, bis(methylcyclopentadienyl)titanium dichloride,bis(methylcyclopentadienyl)zirconium dichloride, cobaltocene,cyclopentadienyltitanium trichloride, ferrocene, hafnocene dichloride,isopropyl(cyclopentadienyl,-1-flourenyl)zirconium dichloride,molybdocene dichloride, nickelocene, niobocene dichloride, ruthenocene,titanocene dichloride, zirconocene chloride hydride, zirconocenedichloride, and so forth. Polymers made using metallocene catalyststypically have a narrow molecular weight range. For instance,metallocene-catalyzed polymers may have polydispersity numbers(M_(w)/M_(n)) of below 4, controlled short chain branching distribution,and controlled isotacticity.

The melt flow index (MI) of the semi-crystalline polyolefins maygenerally vary, but is typically in the range of about 0.1 grams per 10minutes to about 100 grams per 10 minutes, in some embodiments fromabout 0.5 grams per 10 minutes to about 30 grams per 10 minutes, and insome embodiments, about 1 to about 10 grams per 10 minutes, determinedat 190° C. The melt flow index is the weight of the polymer (in grams)that may be forced through an extrusion rheometer orifice (0.0825-inchdiameter) when subjected to a force of 5000 grams in 10 minutes at 190°C., and may be determined in accordance with ASTM Test Method D1238-E.

The present invention also contemplates the use of thermoplasticpolyurethanes as a component of the core layer of the film.Thermoplastic polyurethanes are generally synthesized from a polyol,organic diisocyanate, and optionally a chain extender. The synthesis ofsuch melt-processable polyurethane elastomers may proceed eitherstepwise (e.g., prepolymer dispensing process) or by simultaneousreaction of all components in a single stage (e.g., one-shot dispensingprocess) as is known in the art and described in more detail in U.S.Pat. No. 3,963,656 to Meisert, et al., U.S. Pat. No. 5,605,961 to Lee,et al., U.S. Pat. No. 6,008,276 to Kalbe, et al., U.S. Pat. No.6,417,313 to Kirchmeyer, et al., and U.S. Pat. No. 7,045,650 to Lawrey,et al., as well as U.S. Patent Application Publication Nos. 2006/0135728to Peerlings, et al. and 2007/0049719 to Brauer, et al., all of whichare incorporated herein in their entirety by reference thereto for allpurposes.

Thermoplastic polyurethanes can typically have a melting point of fromabout 75° C. to about 250° C., in some embodiments from about 100° C. toabout 240° C., and in some embodiments, from about 120° C. to about 220°C. The glass transition temperature (“T_(g)”) of the thermoplasticpolyurethane may be relatively low, such as from about −150° C. to about0° C., in some embodiments from about −100° C. to about −10° C., and insome embodiments, from about −85° C. to about −20° C. The meltingtemperature and glass transition temperature may be determined usingdifferential scanning calorimetry (“DSC”) in accordance with ASTMD-3417. Examples of such thermoplastic polyurethanes are available underthe designation DESMOPAN™ from Bayer MaterialScience and under thedesignation ESTANE™ from Lubrizol. DESMOPAN™ DP 9370A, for instance, isan aromatic polyether-based polyurethane formed from poly(tetramethyleneether glycol) and 4,4-methylenebis(phenylisocyanate) (“MDI”) and has aglass transition temperature of about −70° C. and a melting temperatureof from about 188° C. to about 199° C. ESTANE™ 58245 is likewise anaromatic polyether-based polyurethane having a glass transitiontemperature of about −37° C. and a melting temperature of from about135° C. to about 159° C.

The present invention also contemplates the use of thermoplastic esterelastomers and thermoplastic ether elastomers. Of course, besideselastomeric polymers, generally inelastic thermoplastic polymers mayalso be used so long as they do not adversely affect the elasticity ofthe laminate. For example, the thermoplastic composition of the corelayer may contain other polyolefins (e.g., polypropylene, polyethylene,etc.). In one embodiment, the thermoplastic composition may contain anadditional propylene polymer, such as homopolypropylene or a copolymerof propylene. The additional propylene polymer may, for instance, beformed from a substantially isotactic polypropylene homopolymer or acopolymer containing equal to or less than about 10 wt. % of othermonomer, i.e., at least about 90% by weight propylene. Such apolypropylene may be present in the form of a graft, random, or blockcopolymer and may be predominantly crystalline in that it has a sharpmelting point above about 110° C., in some embodiments about above 115°C., and in some embodiments, above about 130° C. Examples of suchadditional polypropylenes are described in U.S. Pat. No. 6,992,159 toDatta, et al., which is incorporated herein in its entirety by referencethereto for all purposes.

b. Skin Layers

As discussed above, it is to be understood that the elastic filmcomponent of the elastic nonwoven laminate of the present invention maybe monolayered or multilayered. Multilayered films may be prepared byco-extrusion or any other conventional layering technique. Whenemployed, the multilayered film can typically contain at least onethermoplastic skin layer and at least one core layer (as discussedabove). For instance, the thermoplastic skin layer(s) may be employed toprovide strength and integrity to the resulting multilayered film viaimproved tensile strength, while the elastic core layer may be employedto provide elasticity to the multilayered film. However, it is also tobe understood that, in some embodiments, the skin layer(s) can includethe elastic components that are discussed above in reference to the corelayer, and the core layer can include the strength and integritycomponents discussed herein in reference to the skin layer(s).

In one particular embodiment of the present invention, the film includesat least one elastic core layer positioned between at least twothermoplastic skin layers. In such embodiments, the core layer canprovide the desired degree of elasticity to the multilayered film. Toimpart the desired elastic properties to the film, elastomers canconstitute about 55 wt. % or more, in some embodiments about 60 wt. % ormore, and in some embodiments, from about 65 wt. % to about 100 wt. % ofthe polymer content of the elastomeric composition used to form the corelayer. In fact, in certain embodiments, the core layer may be generallyfree of polymers that are inelastic. For example, such inelasticpolymers may constitute about 15 wt. % or less, in some embodimentsabout 10 wt. % or less, and in some embodiments, about 5 wt. % or lessof the polymer content of the elastomeric composition.

Meanwhile, although the skin layers may possess some degree ofelasticity and may, in some embodiments, be formed from any of thematerials discussed above, in some embodiments, such layers may beformed from a thermoplastic composition that is less elastic than theelastic layer(s) to ensure that the strength of the film is sufficientlyenhanced. For example, one or more elastic layers may be formedprimarily from substantially amorphous elastomers (e.g., styrene-olefincopolymers) and one or more thermoplastic layers may be formed frompolyolefin plastomers (e.g., single-site catalyzed ethylene or propylenecopolymers), which are described in more detail above. Althoughpossessing some elasticity, such polyolefins are generally less elasticthan substantially amorphous elastomers. Of course, the thermoplasticlayer(s) may contain generally inelastic polymers, such as conventionalpolyolefins, (e.g., polyethylene), low density polyethylene (LDPE),Ziegler-Natta catalyzed linear low density polyethylene (LLDPE), etc.),ultra low density polyethylene (ULDPE), polypropylene, polybutylene,etc.; polytetrafluoroethylene; polyesters, e.g., polyethyleneterephthalate (PET), etc.; polyvinyl acetate; polyvinyl chlorideacetate; polyvinyl butyral; acrylic resins, e.g., polyacrylate,polymethylacrylate, polymethylmethacrylate, etc.; polyamides, e.g.,nylon; polyvinyl chloride; polyvinylidene chloride; polystyrene;polyvinyl alcohol; polyurethanes; polylactic acid; copolymers andmixtures thereof; and so forth. For instance, the skin layers can beformed from an LLDPE available from Dow Chemical Co. of Midland, Mich.,such as DOWLEX™ 2517 or DOWLEX™ 2047, or a combination thereof, orWestlake Chemical Corp. of Houston, Tex. In certain embodiments,polyolefins (e.g., conventional and/or plastomers) can be employed andconstitute about 55 wt. % or more, in some embodiments about 60 wt. % ormore, and in some embodiments, from about 65 wt. % to 100 wt. % of thepolymer content of the thermoplastic composition used to form the skinlayers. Regardless of the components used in forming the skin layers,the skin layers generally have an elongation at break that is greaterthan about 300%.

The weight percentages of the core and skin layers in the elastic filmcan be generally selected so as to achieve an appropriate balancebetween film elasticity and strength. For instance, the thickness of thecore layer can typically range from about 20 to about 200 micrometers,in some embodiments from about 25 to about 175 micrometers, and in someembodiments, from about 30 to about 150 micrometers. The core layer mayalso constitute from about 50 wt. % to about 99 wt. % of the totalweight of the film, in some embodiments from about 70 wt. % to about 98wt. % of the total weight of the film, and in some embodiments fromabout 85% to about 97% of the total weight of the film. On the otherhand, the thickness of the one or more skin layers can typically rangefrom about 0.5 to about 20 micrometers, in some embodiments from about 1to about 15 micrometers, and in some embodiments, from about 2 to about12 micrometers. The skin layer(s) may also constitute from about 1 wt. %to about 50 wt. % of the total weight of the film, in some embodimentsfrom about 2 wt. % to about 20 wt. % of the total weight of the film,and in some embodiments from about 3 wt. % to about 15 wt. %, and insome embodiments from about 5 wt. % to about 10 wt. % of the totalweight of the film. In one particular embodiment, an elastic core layercan be sandwiched between two thermoplastic skin layers, where thethickness of each of the skin layers is equal. For example, in oneembodiment, the film can include a core layer that constitutes 96% ofthe total weight of the film, while the skin layers each constitute 2%of the total weight of the film. The film may also have a totalthickness of from about 20 to about 250 micrometers, in someembodiments, from about 25 to about 225 micrometers, and in someembodiments, from about 30 to about 200 micrometers.

c. Other Film Components

Further, the various layers of the film of the present invention mayalso contain other components as are known in the art. In oneembodiment, for example, one or more of the film layers can include afiller. Fillers are particulates or other forms of material that may beadded to the film polymer extrusion blend and that will not chemicallyinterfere with the extruded film, but which may be uniformly dispersedthroughout the film. Fillers may serve a variety of purposes, includingenhancing film opacity and/or breathability (i.e., vapor-permeable andsubstantially liquid-impermeable). For instance, filled films may bemade breathable by stretching, which causes the polymer to break awayfrom the filler and create microporous passageways. Breathablemicroporous elastic films are described, for example, in U.S. Pat. No.5,932,497 to Morman, et al., U.S. Pat. Nos. 5,997,981, 6,015,764, and6,111,163 to McCormack, et al., and U.S. Pat. No. 6,461,457 to Taylor,et al., which are incorporated herein in their entirety by referencethereto for all purposes. Examples of suitable fillers include, but arenot limited to, calcium carbonate, various kinds of clay, silica,alumina, barium carbonate, sodium carbonate, magnesium carbonate, talc,barium sulfate, magnesium sulfate, aluminum sulfate, titanium dioxide(e.g., SCC 11692 concentrated titanium dioxide), zeolites,cellulose-type powders, kaolin, mica, carbon, calcium oxide, magnesiumoxide, aluminum hydroxide, pulp powder, wood powder, cellulosederivatives, chitin and chitin derivatives. In certain cases, the fillercontent of the film may range from about 0.1 wt. % to about 10 wt. %, insome embodiments, from about 0.5 wt. % to about 7.5 wt. %, and in someembodiments, from about 1 wt. % to about 5 wt. % of the film based onthe total weight of the film.

Other additives may also be incorporated into the film, such as meltstabilizers, crosslinking catalysts, pro-rad crosslinking additives,processing stabilizers, heat stabilizers, light stabilizers,antioxidants, heat aging stabilizers, whitening agents, antiblockingagents, bonding agents, tackifiers, viscosity modifiers, etc. Examplesof suitable tackifier resins may include, for instance, hydrogenatedhydrocarbon resins. REGALREZ™ hydrocarbon resins are examples of suchhydrogenated hydrocarbon resins, and are available from EastmanChemical. Other tackifiers are available from ExxonMobil under theESCOREZ™ designation. Viscosity modifiers may also be employed, such aspolyethylene wax (e.g., EPOLENE™ C-10 from Eastman Chemical). Phosphitestabilizers (e.g., IRGAFOS™ 168 available from Ciba Specialty Chemicalsof Tarrytown, N.Y. and DOVERPHOS™ available from Dover Chemical Corp. ofDover, Ohio) are exemplary melt stabilizers. In addition, hindered aminestabilizers (e.g., CHIMASSORB™ available from Ciba Specialty Chemicals)are exemplary heat and light stabilizers. Further, hindered phenols arecommonly used as an antioxidant in the production of films. Somesuitable hindered phenols include those available from Ciba SpecialtyChemicals under the trade name IRGANOX™, such as IRGANOX™ 1076, 1010, orE 201. Moreover, bonding agents may also be added to the film tofacilitate bonding of the film to additional materials (e.g., a nonwovenfacing). Typically, such additives (e.g., tackifier, antioxidant,stabilizer, etc.) can each be present in an amount from about 0.001 wt.% to about 25 wt. %, in some embodiments, from about 0.005 wt. % toabout 20 wt. %, and in some embodiments, from about 0.01 wt. % to about15 wt. % of the film based on the total weight of the film.

Regardless of the particular film content, the film and/or the materialsused to form the film may also be subjected to one or more additionalprocessing steps. In one embodiment, for example, an elastomeric polymeremployed in the film can be crosslinked, before, after, and/or duringlamination to a nonwoven facing, to provide the film with enhancedelastic characteristics. Crosslinking may be induced by subjecting thepolymer to electromagnetic radiation, such as ultraviolet light,electron beam radiation, natural and artificial radio isotopes (e.g., α,β, and γ rays), x-rays, neutron beams, positively-charged beams, laserbeams, and so forth. The wavelength (“λ”) of the electromagneticradiation may be about 1000 nanometers or less, in some embodimentsabout 100 nanometers or less, and in some embodiments, about 1 nanometeror less. Electron beam radiation, for instance, typically has awavelength of about 1 nanometer or less. The total dosage absorbed (inone or multiple steps) may likewise range from about 10 kilograys (kGy)to about 300 kGy, in some embodiments, from about 50 kGy to about 200kGy, and in some embodiments, from about 75 to about 150 kGy. Inaddition, the energy level may range from about 10 kiloelectron volts(keV) to about 300 keV, such as from about 50 keV to about 200 keV, suchas from about 75 keV to about 150 keV. Upon crosslinking, athree-dimensional crosslinked network may be formed that provides thematerial with additional elasticity in the machine direction,cross-machine direction, or both.

II. Nonwoven Facing

In addition to the elastic film, the elastic nonwoven laminate of thepresent disclosure may also include one or more nonwoven facing layersthat can serve as an exterior surface of the laminate. The nonwovenfacing layers, for instance, may comprise a nonwoven material, such as aspunbond web or a meltblown web. The spunbond or meltblown nonwovenfacing can include a polyolefin, and, in some embodiments, can include acombination of a polyolefin and a polyolefin-based plastomer. Forexample, in some embodiments, the spunbond or meltblown nonwoven facingcan include a polyethylene and a polyethylene-based plastomer or apolypropylene and a polypropylene-based plastomer. In other embodiments,the spunbond or meltblown nonwoven facing can include a combination ofany of the following: polyethylene, polypropylene, a polyethylene-basedplastomer, and/or a polypropylene-based plastomer.

Polyethylenes that can be used to form the nonwoven facing layer includeconventional polyethylene and low density polyethylene (LDPE). Othersuitable ethylene polymers are available from The Dow Chemical Companyunder the designations ASPUN™ (LLDPE), DOWLEX™ (LLDPE) and ATTANET™(ULDPE). Other suitable ethylene polymers are described in U.S. Pat. No.4,937,299 to Ewen, et al., U.S. Pat. No. 5,218,071 to Tsutsui et al.,U.S. Pat. No. 5,272,236 to Lai, et al., and U.S. Pat. No. 5,278,272 toLai, et al., which are incorporated herein in their entirety byreference thereto for all purposes.

In addition, polyethylene-based plastomers can be used in conjunctionwith the aforementioned polyethylenes when forming the spunbond ormeltblown nonwoven facing layer. Such ethylene-based plastomers includeethylene-based copolymer plastomers available under the designationEXACT™ from ExxonMobil Chemical Company of Houston, Tex. Other suitablepolyethylene plastomers are available under the designation ENGAGE™ andAFFINITY™ from Dow Chemical Company of Midland, Mich. An additionalsuitable polyethylene-based plastomer is an olefin block copolymeravailable from Dow Chemical Company of Midland, Mich. under the tradedesignation INFUSE™.

Of course, the present invention is by no means limited to the use ofethylene polymers. For instance, conventional polypropylene can be acomponent of the spunbond or meltblown nonwoven facing layer. Further,propylene plastomers may also be suitable for use in the nonwoven facinglayers in combination with conventional polypropylene. Suitableplastomeric propylene polymers may include, for instance, copolymers orterpolymers of propylene, copolymers of propylene with an α-olefin(e.g., C₃-C₂₀), such as ethylene, 1-butene, 2-butene, the variouspentene isomers, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-unidecene,1-dodecene, 4-methyl-1-pentene, 4-methyl-1-hexene, 5-methyl-1-hexene,vinylcyclohexene, styrene, etc. The comonomer content of the propylenepolymer may be about 35 wt. % or less, in some embodiments from about 1wt. % to about 20 wt. %, and in some embodiments, from about 2 wt. % toabout 10 wt. %. Preferably, the density of the polypropylene (e.g.,propylene/α-olefin copolymer) may be 0.91 g/cm³ or less, in someembodiments, from 0.85 g/cm³ to 0.88 g/cm³, and in some embodiments,from 0.85 g/cm³ to 0.87 g/cm³. Suitable propylene polymers arecommercially available under the designations VISTAMAXX™ (e.g., 6102), apropylene-based elastomer from ExxonMobil Chemical Co. of Houston, Tex.;FINA™ (e.g., 8573) from Atofina Chemicals of Feluy, Belgium; TAFMER™available from Mitsui Petrochemical Industries; and VERSIFY™ availablefrom Dow Chemical Co. of Midland, Mich. Other examples of suitablepropylene polymers are described in U.S. Pat. No. 5,539,056 to Yang, etal., U.S. Pat. No. 5,596,052 to Resconi, et al., and U.S. Pat. No.6,500,563 to Datta, et al., which are incorporated herein in theirentirety by reference thereto for all purposes.

Regardless of the particular combination of polyolefins and/orpolyolefin-based plastomers employed in the nonwoven facing layer(s) ofthe present disclosure, a polyolefin can be present in the nonwovenfacing layer(s) in an amount up to about 100%, such as an amount rangingfrom about 40 wt. % to about 100 wt. %, such as an mount ranging fromabout 50 wt. % to about 99 wt. %, such as an amount ranging from about60 wt. % to about 98 wt. % based on the total weight of the nonwovenfacing layer(s). Meanwhile, a polyolefin-based plastomer can be presentin the nonwoven facing layer(s) in an amount ranging from about 0.5 wt.% to about 60 wt. %, such as from about 1 wt. % to about 50 wt. %, suchas from about 2 wt. % to about 40 wt. % based on total weight of thenonwoven facing layers.

Further, the fillers discussed above in Section I(c) in reference to theelastic film can also be utilized in the nonwoven web material of thepresent disclosure. When utilized, the amount of fillers present in thenonwoven facing can range from about 0.1 wt % to about 10 wt. %, in someembodiments, from about 0.5 wt. % to about 7.5 wt. %, and in someembodiments, from about 1 wt. % to about 5 wt. % of the nonwoven facingbased on the total weight of the nonwoven facing.

Monocomponent and/or multicomponent fibers may be used to form thenonwoven web material. Monocomponent fibers are generally formed from apolymer or blend of polymers extruded from a single extruder.Multicomponent fibers are generally formed from two or more polymers(e.g., bicomponent fibers) extruded from separate extruders. Thepolymers may be arranged in substantially constantly positioned distinctzones across the cross-section of the fibers. The components may bearranged in any desired configuration, such as sheath-core,side-by-side, pie, island-in-the-sea, three island, bull's eye, orvarious other arrangements known in the art and so forth. Variousmethods for forming multicomponent fibers are described in U.S. Pat. No.4,789,592 to Taniguchi, et al., U.S. Pat. No. 4,795,668 to Kruege, etal., U.S. Pat. No. 5,108,820 to Kaneko, et at, U.S. Pat. No. 5,336,552to Strack, et al., U.S. Pat. No. 5,382,400 to Pike, et al., and U.S.Pat. No. 6,200,669 to Marmon, et al., which are incorporated herein intheir entirety by reference thereto for all purposes. Multicomponentfibers having various irregular shapes may also be formed, such asdescribed in U.S. Pat. No. 5,057,368 to Largman, et al., U.S. Pat. No.5,069,970 to Largman, et al., U.S. Pat. No. 5,162,074 to Hills, U.S.Pat. No. 5,277,976 to Hogle, et al., and U.S. Pat. No. 5,466,410 toHills, which are incorporated herein in their entirety by referencethereto for all purposes.

If desired, the nonwoven facing used to form the elastic nonwovenlaminate of the present invention may have a multi-layer structure.Suitable multi-layered materials may include, for instance,spunbond/meltblown/spunbond (SMS) laminates and spunbond/meltblown (SM)laminates. Various examples of suitable SMS laminates are described inU.S. Pat. No. 4,041,203 to Brock et al., U.S. Pat. No. 4,374,888 toBornslaeger, U.S. Pat. No. 4,766,029 to Brock et al., U.S. Pat. No.5,169,706 to Collier et al., U.S. Pat. No. 5,213,881 to Timmons et al.,and U.S. Pat. No. 5,464,688 to Timmons, et al., which are incorporatedherein in their entirety by reference thereto for all purposes. Inaddition, commercially available SMS laminates may be obtained fromKimberly-Clark Corporation under the designations Spunguard® andEvolution®.

Another example of a multi-layered structure is a spunbond web producedon a multiple spin bank machine in which a spin bank deposits fibersover a layer of fibers deposited from a previous spin bank. Such anindividual spunbond nonwoven facing may also be thought of as amulti-layered structure. In this situation, the various layers ofdeposited fibers in the nonwoven web may be the same, or they may bedifferent in basis weight and/or in terms of the composition, type,size, level of crimp, and/or shape of the fibers produced. As anotherexample, a single nonwoven facing may be provided as two or moreindividually produced layers of a spunbond web, a meltblown web, etc.,which have been bonded together to form the nonwoven facing. Theseindividually produced layers may differ in terms of production method,basis weight, composition, etc. as discussed above.

The basis weight of each of the nonwoven facing layers may generallyvary, such as from about 1 gsm to about 120 gsm, such as from about 5gsm to about 80 gsm, such as from about 10 gsm to about 60 gsm, such asfrom about 15 gsm to about 40 gsm. When multiple nonwoven facings areutilized, such materials may have the same or different basis weights.

III. Lamination, Grooving and Bonding Techniques

a. Lamination

Any of a variety of techniques may be employed to laminate the elasticfilm and nonwoven facing layers discussed above together to form theelastic nonwoven laminate of the present invention, including adhesivebonding, thermal bonding, ultrasonic bonding, microwave bonding,extrusion coating, and so forth. In one particular embodiment, nip rollsapply a pressure to the elastic film and nonwoven facing(s) to thermallybond the layers together. The rolls may be smooth and/or contain aplurality of raised bonding elements. In one embodiment, a laminatecontaining an elastic film sandwiched between two nonwoven facing layerscan be formed. The rolls used to join the film to the nonwoven facinglayers can be smooth chill rolls, and the nonwoven facing layers can belaminated to the film by extrusion casting the elastic film between twofacing materials as the film and facing materials pass through the nipbetween the chilled rolls. In another embodiment, an already-cast filmcan be disposed between the nonwoven facing layers and adhesively bondedto the nonwoven facing layers. Adhesives that can be employed caninclude BOSTIK™ H2494 available from Bostik Findley, Inc, of Wauwatosa,Wis. and REXTAC™ 2730 and 2723 available from Huntsman Polymers ofHouston, Tex. The type and basis weight of the adhesive used will bedetermined on the elastic attributes desired in the final composite andend use. For instance, the basis weight of the adhesive may be fromabout 0.5 gsm to about 3 gsm, such as from about 0.75 gsm to about 1.75gsm, such as from about 1 gsm to about 1.5 gsm. The adhesive may beapplied to the nonwoven web facings and/or the elastic material prior tolamination using any known technique, such as by ribbon, slot, meltspray, of dot pattern adhesive systems.

FIG. 1 schematically illustrates an exemplary process 100 for forming anelastic nonwoven laminate in this manner. Initially, an elastic film 126is passed between a first set of nip rolls 132 and 134, and a second setof nip rolls 136 and 138. Further, nonwoven facing layers 124 and 128are also unwound from storage rolls 122 and 130 and combined with theelastic film 126 to form a composite 140 between nip rolls 136 and 138.The layers may be combined with the aid of an adhesive applied to thenonwoven layers or the precursor layer, or with the aid of heat suppliedfrom roll 136 and/or 138. After the composite 140 is formed, it may thenbe subjected to additional processing steps at location 146 (e.g.,grooving, bonding, etc. as discussed below) before being wound onto aroll 144. Further, in some embodiments, prior to attaching the film tothe nonwoven facings, the film can be e-beam crosslinked. In otherembodiments, the film can be attached to a nonwoven facing on one side,then can be e-beam crosslinked, and then can be attached to a secondnonwoven facing on the opposing side. For instance, when a facingcontains polypropylene, it cannot be attached to the film prior toe-beam crosslinking because the polypropylene would degrade.

Although a three-layer laminate is shown in FIG. 1 having an elasticfilm, which itself can be multilayered (e.g., a core layer that provideselasticity sandwiched between two skin layers that provide strength or acore layer that provides strength sandwiched between two skin layersthat provide elasticity) disposed between two nonwoven facings, otherarrangements are also contemplated by the present disclosure. Forinstance, in one embodiment, a monolayered elastic film can be disposedbetween two nonwoven facing layers. In another embodiment, the elasticnonwoven laminate can include two film layers and three nonwoven facinglayers. For example, the laminate can be arranged in the followingorder; spunbond facing, film, meltblown facing, film, spunbond facing,where the two film layers can be monolayered or multilayered. When thefilms are multilayered, the following arrangement is contemplated:spunbond facing, skin film layer, core film layer, meltblown facing,core film layer, skin film layer, spunbond facing. By having a meltblownfacing disposed in the middle of the laminate, the resulting laminatecan be provided with the desired level of loftiness.

Further, it is also to be understood that in addition to the method offorming the laminate discussed above, the film alternatively can beextrusion cast between nonwoven facing layers instead of being firstcast and then adhesively bonded to the nonwoven facing layer(s).

b. Grooving

While only generally referenced at location 146 in FIG. 1, variousadditional potential processing and/or finishing steps known in the art,such as slitting, treating, printing graphics, etc., may be performedwithout departing from the spirit and scope of the invention. Forinstance, the laminate may be activated in the cross-machine and/ormachine directions to enhance extensibility by decoupling the nonwovenfacing from the elastic film of the laminate. In one embodiment, thecomposite may be coursed through two or more rolls that have grooves inthe CD and/or MD directions. Such grooved satellite/anvil rollarrangements are described in U.S. Patent Application Publication Nos.2004/0110442 to Rhim, et al. and 2006/0151914 to Gerndt, et al., whichare incorporated herein in their entirety by reference thereto for allpurposes. For instance, the laminate may be coursed through two or morerolls that have grooves in the CD and/or MD directions. The groovedrolls may be constructed of steel or other hard material (such as a hardrubber).

FIGS. 2-3 further illustrate the manner in which groove rolls maydecouple the nonwoven facing from the elastic portion of the composite.As shown, for example, satellite rolls 182 may engage an anvil roll 184,each of which include a plurality of ridges 183 defining a plurality ofgrooves 185 positioned across the grooved rolls in the cross-machinedirection. The grooves 185 are generally oriented perpendicular to thedirection of stretch of the material. In other words, the grooves 185are oriented in the machine direction to stretch the composite in thecross-machine direction. The grooves 185 may likewise be oriented in thecross-machine direction to stretch the composite in the machinedirection. The ridges 183 of satellite roll 182 intermesh with thegrooves 185 of anvil roll 184, and the grooves 185 of satellite roll 182intermesh with the ridges 183 of anvil roll 184.

The dimensions and parameters of the grooves 185 and ridges 183 mayvary. In general, the groove rolls can include grooves that are evenlyspaced along the length of the groove face or unevenly spaced. Forexample, the number of grooves 185 contained on a roll may generallyrange from about 1 and 12 grooves per inch, in some embodiments fromabout 2 and 10 grooves per inch, and in some embodiments, from about 3and 8 grooves per inch. The grooves 185 may also have a certain depth“D”, which generally ranges from about 0.05 inches to about 1 inch, insome embodiments, from about 0.075 inches to about 0.5 inches, and insome embodiments, from about 0.1 inches to about 0.3 inches. Inaddition, the peak-to-peak distance “P” between the grooves 185 istypically from about 0.05 inches to about 1 inch, in some embodimentsfrom about 0.075 inches to about 0.5 inches, and in some embodiments,from about 0.1 inches to about 0.25 inches. Further, the laminate can beengaged at a depth ranging from about to about 90%, such as from about30% to about 85%, such as from about 50% to 80% of the depth of thegrooves.

If desired, heat may be applied to the composite or laminate just priorto or during the application of the grooves to cause it to relaxsomewhat and ease extension. Heat may be applied by any suitable methodknown in the art, such as heated air, infrared heaters, heated nippedrolls, or partial wrapping of the laminate around one or more heatedrolls or steam canisters, etc. Heat may also be applied to the groovedrolls themselves. It should also be understood that other grooved rollarrangement are equally suitable, such as two grooved rolls positionedimmediately adjacent to one another. In another embodiment, the processmay include a grooved roll that contacts a flat anvil roll which mayhave a deformable surface.

Regardless of other formation techniques utilized, the laminate 140(FIG. 3) may be stretched in one or more directions at a stretch ratioof from about 1.5 to about 8.0, in some embodiments by at least about2.0 to about 6.0, and in some embodiments, from about 2.5 to about 4.5.The stretch ratio is determined by dividing the stretched length of amaterial by the original length of the material. In other words, thestretch ratio is equal to the original length of the material plus thechange in length of the material upon stretching, divided by theoriginal length, which is also the sum of the strain plus one.

c. Post-Bonding

After the laminate has been formed via attaching the elastic film to thenonwoven as discussed above, and after the nonwoven facing has beendecoupled from the elastic film via grooving to activate machinedirection and or cross-machine direction stretchability of the laminate,typically, with spunbond or meltblown nonwoven facings, the fibers inthe nonwoven facing can separate from each other, pull out, and create a“fuzzy” appearance. These facings can also have insufficient shear andpeel properties for use in certain absorbent article applications, whichcan prevent the use of meltblown or spunbond nonwoven facings inlaminates where fiber pullout is a concern, such as in materialsutilizing reusable fastening/attachment mechanisms.

Meanwhile, post-bonding of an outer surface of the nonwoven facingmaterial can reduce fiber pull out and the fuzzy appearance of meltblownand spunbond nonwoven facings in laminates that have beengroove-activated so that such laminates can be used in applications withminimal fiber pullout, yet without sacrificing the softness or feel ofthe laminates, nor their elastic stretchability and recoverability.Post-bonding of an outer-facing surface of nonwoven facing layer cangenerally be accomplished in the present invention via a smooth calendarroll or via a patterned bonding technique (e.g., thermal point bonding,ultrasonic bonding, etc.) in which the laminate is supplied to a nipdefined by at least one patterned roll. Thermal point bonding, forinstance, typically employs a nip formed between two rolls, at least oneof which is patterned. Ultrasonic bonding, on the other hand, typicallyemploys a nip formed between a sonic horn and a patterned roll.Regardless of the technique chosen, the patterned roll can contain aplurality of bonding elements to bond the film to the nonwoven webmaterial(s) and, in some embodiments, form apertures in the nonwovenfacing, such as when the laminate is used as a side panel in anabsorbent article and should be breathable. The size of the bondingelements may be specifically tailored to enhance bonding of the nonwovenfacing and can also be selected to facilitate the formation of aperturesin the nonwoven facing and, in some embodiments, the film layer of thelaminate. For example, the bonding elements are typically selected tohave a relatively large length dimension. The length dimension of thebonding elements may be from about 300 to about 5000 micrometers, insome embodiments from about 500 to about 4000 micrometers, and in someembodiments, from about 1000 to about 2000 micrometers. The widthdimension of the bonding elements may likewise range from about 20 toabout 500 micrometers, in some embodiments from about 40 to about 200micrometers, and in some embodiments, from about 50 to about 150micrometers. In addition, the “element aspect ratio” (the ratio of thelength of an element to its width) may range from about 2 to about 100,in some embodiments from about 4 to about 50, and in some embodiments,from about 5 to about 20.

Besides the size of the bonding elements, the overall bonding patternmay also be selectively controlled to achieve the desired bond formationon an outer surface of the nonwoven facing. In one embodiment, thenonwoven facing layer(s) can be point unbonded or “PUB” bonded. “Pointunbonded” or “PUB” bonding means a facing pattern having continuousbonded areas defining a plurality of discrete unbonded areas. The fibersor filaments within the discrete unbonded areas are dimensionallystabilized by the continuous bonded areas that encircle or surround eachunbonded area and the unbonded areas are specifically designed to affordspaces between fibers or filaments within the unbonded areas. A suitableprocess for forming the pattern-unbonded nonwoven facing of the presentinvention includes providing a nonwoven facing, providing opposedlypositioned first and second calender rolls and defining a niptherebetween, with at least one of said rolls being heated and having abonding pattern on its outermost surface comprising a continuous patternof land areas defining a plurality of discrete openings, apertures orholes, and passing the nonwoven facing within the nip formed by saidrolls. Each of the openings in said roll or rolls defined by thecontinuous land areas forms a discrete unbonded area in at least onesurface of the nonwoven facing in which the fibers or filaments of thefacing are substantially or completely unbonded. Stated alternatively,the continuous pattern of land areas in said roll or rolls forms acontinuous pattern of bonded areas that define a plurality of discreteunbonded areas on at least one surface of said nonwoven facing.

After the laminate of the present invention is formed, the laminate ispassed through a suitable process and apparatus to form thepattern-unbonded nonwoven loop material of the present invention.Referring now to FIGS. 4 and 5, a process and apparatus for forming thepattern-unbonded nonwoven facing of the present invention now will bedescribed. In FIG. 4, apparatus for forming the pattern-unbondednonwoven loop material of this invention is represented generally aselement 434. The apparatus includes a first facing unwind 436 for afirst laminate 438. Optionally, one or more additional rolls 437 (shownin phantom) for additional laminates 439 may be employed in formingmulti-layer pattern-unbonded laminates. It should be understood thatalthough the apparatus shown in FIG. 4 illustrates a laminate unwind436, the pattern-unbonding assembly 400 may be placed in a continuous(in-line) process with the laminate forming equipment described herein,as shown in FIG. 1 as reference numeral 146. As used herein, the term“pattern-unbonding assembly” should not be construed as apparatus fordisassembling, destroying or removing existing bonds, if any, inlaminate 438; rather, pattern-unbending assembly refers to an apparatusthat continuously bonds or fuses the fibers or filaments forming thenonwoven facing of laminate 438 in specified areas of the web, andprevents bonding or fusing of the fibers or filaments of the nonwovenfacing of laminate 438 in other specified areas of the web, such areasbeing referred to herein as bonded areas and unbonded areas,respectively.

First laminate 438 is taken off the unwind 436 and passed into apattern-unbonding assembly 400 that includes a first or patterned roll442 and a second or anvil roll 444, both of which are driven byconventional drive means, such as, for example, electric motors (notshown). Patterned roll 442 is a right circular cylinder that may beformed of any suitable, durable material, such as, for example, steel,to reduce wear on the rolls during use. Patterned roll 442 has on itsoutermost surface a pattern of land areas 446 that define a plurality ofdiscrete openings or apertures 448. The land areas 446 are designed toform a nip with the smooth or flat outer surface of opposedly positionedanvil roll 444, which also is a right circular cylinder that can beformed of any suitable, durable material.

The size, shape, number, and configuration of openings 448 in patternedroll 442 can be varied to meet the particular end-use needs of thepattern-unbonded nonwoven facing of the laminate being formed thereby.In order to reduce the incidence of fiber pull-out in the resultinglaminate material, the size of openings 448 in patterned roll 442 can bedimensioned to reduce the likelihood that the entire length of thefilaments or fibers forming an unbonded area will lie within a singleunbonded area, Stated differently, fiber length should be selected toreduce the likelihood that the entire length of a given fiber orfilament will fall within a single unbonded area. On the other hand, thedesirability of restricting the size of the openings 448 in patternedroll 442, and the unbonded areas 608 formed thereby in thepattern-unbonded nonwoven facing 600 of FIG. 6, is counter-balanced bythe need for the unbonded areas 608 to have sufficient size to providethe required engagement areas for the hook elements of a complementaryhook material, in applications where, for example, the elastic nonwovenlaminates is used as part of a fastening system in an absorbent article.The bonding areas can also be minimized so that the resulting laminatematerial maintains a desired level of loftiness.

Circular openings 448 as shown in FIG. 5 hereof having an averagediameter ranging from about 0.050 inch (about 0.127 cm) to about 0.250inch (about 0.635 cm), such as from about 0.130 inch (0.330 cm) to about0.160 inch (0.406 cm), and a depth measured from the outermost surfaceof patterned roll 442 of at least about 0.020 inch (about 0.051 cm),such as from about 0.060 inch (0.152 cm), are considered suitable informing the pattern-unbonded nonwoven material of the present invention.While openings 448 in patterned roll 442 as shown in FIG. 5 arecircular, other shapes, such as ovals, squares, diamonds and the likecan be advantageously employed.

The number or density of openings 448 in patterned roll 442 also can beselected to provide the requisite amount of engagement areas for, forinstance, hook elements in an absorbent article, without unduly limitingthe size of the continuous bonded areas and giving rise to increasedincidence of fiber pull-out. Pattern rolls having an opening density inthe range of from about 1 opening per square centimeter (cm²) to about25 openings/cm², such as from about 5 openings/cm² to about 7openings/cm², may be utilized to advantage in forming thepattern-unbonded nonwoven facing in the laminate of the presentinvention.

Moreover, the spacing between individual openings 448 can be selected toenhance the hook engagement functionality of the resulting laminateincluding the pattern-unbonded nonwoven facing, which can, in someembodiments, be used as a loop material, without overly reducing theportion of the pattern-unbonded loop material occupied by continuousbonded areas, which serve to lessen fiber pull-out. Suitableinter-opening spacings for the embodiment shown can range from about0.13 inch (about 3.30 mm) to about 0.22 inch (about 5.59 mm),centerline-to-centerline, in the machine and cross-machine directions,

The particular arrangement or configuration of openings 448 in patternedroll 442 is not considered critical, so long as in combination with theopening size, shape and density, the desired levels of surfaceintegrity, loftiness, durability, peel strength, etc. can be achieved.For example, as shown in FIG. 5, the individual openings 448 arearranged in staggered rows. Other different configurations areconsidered within the scope of the present invention.

The portion of the outermost surface of the patterned roll 442 occupiedby continuous land areas 446 likewise can be modified to satisfy thecontemplated end-use application of the pattern-unbonded material. Thedegree of bonding imparted to the pattern-unbonded nonwoven facing ofthe laminate by the continuous land areas 446 can be expressed as apercent bond area, which refers to the portion of the total plan area ofat least one outer surface of a pattern-unbonded nonwoven facing 600(see FIG. 6) that is occupied by bonded areas 606 and unbonded areas608. Stated generally, the lower limit on the percent bond area suitablefor forming the pattern-unbonded nonwoven facing 600 of the presentinvention is the point at which fiber pull-out excessively reduces thesurface integrity and durability of the pattern-unbonded material. Therequired percent bond area will be affected by a number of factors,including the type(s) of polymeric materials used in forming the fibersor filaments of the nonwoven facing, whether the nonwoven facing is asingle- or multi-layer fibrous structure, whether the nonwoven facing isunbonded or pre-bonded prior to passing into the pattern-unbondingassembly, and the like. Pattern-unbonded nonwoven facings having percentbond areas ranging from about 10% to about 60%, such as from about 15%to about 55%, such as from about 20% to about 50% based on the totalsurface area of the nonwoven facing, have been found suitable.

The temperature of the outer surface of patterned roll 442 can be variedby heating or cooling relative to anvil roll 444. Heating and/or coolingcan affect the features of the laminate(s) being processed and thedegree of bonding of single or multiple laminates being passed throughthe nip formed between the counterrotating patterned roll 442 and anvilroll 444. In the embodiment shown in FIG. 4, for example, both patternedroll 442 and anvil roll 444 are heated, desirably to the same bondingtemperature. The specific ranges of temperatures to be employed informing the pattern-unbonded nonwoven facing is dependent upon a numberof factors, including the types of polymeric materials employed informing the pattern-unbonded nonwoven facing, the inlet or line speed(s)of the nonwoven web(s) passing through the nip formed between patternedroll 442 and anvil roll 444, and the nip pressure between patterned roll442 and anvil roll 444.

Anvil roll 444 as shown in FIG. 4 has an outer surface that is muchsmoother than patterned roll 442, and preferably is smooth or flat. Itis possible, however, for anvil roll 444 to have a slight pattern on itsouter surface and still be considered smooth or flat for purposes of thepresent invention. For example, if anvil roll 444 is made from or has asofter surface, such as resin impregnated cotton or rubber, it willdevelop surface irregularities, yet it will still be considered smoothor flat for purposes of the present invention. Such surfaces arecollectively referred to herein as “flat,” Anvil roll 444 provides thebase for patterned roll 442 and the web or webs of material to contact.Typically, anvil roll 444 will be made from steel, or materials such ashardened rubber, resin-treated cotton or polyurethane.

Alternatively, anvil roll 444 may be replaced with a pattern roll (notshown) having a pattern of continuous land areas defining a plurality ofdiscrete, apertures or openings therein, as in the above-describedpatterned roll 442. In such case, the pattern-unbonding assembly wouldinclude a pair of counter-rotating pattern rolls which would impart apattern of continuous bonded areas defining a plurality of discreteunbonded areas on both the upper and lower surfaces of thepattern-unbonded nonwoven loop material. Rotation of the opposedlypositioned pattern rolls can be synchronized, such that the resultingunbonded areas on the surfaces of the pattern-unbonded material arevertically aligned or juxtaposed.

Referring again to FIG. 4, patterned roll 442 and anvil roll 444 arerotated in opposite directions to one another so as to draw the nonwovenfacing(s) through the nip area defined therebetween. Patterned roll 442has a first rotational speed measured at its outer surface and anvilroll 444 has a second rotational speed measured at its outer surface. Inthe embodiment shown, the first and second rotational speeds aresubstantially identical. However, the rotational speeds of the patternand anvil rolls can be modified to create a speed differential betweenthe counter-rotating rolls.

The locations of the opposedly positioned patterned roll 442 and anvilroll 444 may be varied to create a nip area 450 between the rolls. Thenip pressure within nip area 450 can be varied depending upon theproperties of the web itself or webs themselves and the degree ofbonding desired. Other factors that will allow variances in the nippressure will include the temperatures of the patterned roll 442 andanvil roll 444, the size and spacing of openings 448 in patterned roll442, as well as the types of polymeric materials used in forming thepattern-unbonded nonwoven material. With respect to the degree ofbonding to be imparted to the pattern-unbonded nonwoven loop materialwithin the continuous bonded areas, the pattern-unbonded materialdesirably is thoroughly bonded or melt-fused in the bonded areas, suchthat the polymeric material is rendered non-fibrous. This high degree ofbonding is important in stabilizing the portions of the fibers orfilaments within the unbonded areas extending into the continuous bondedareas and reducing fiber pull-out when, for example, hook elements for afastening mechanism are disengaged from the discrete unbonded areas.

In another embodiment, for example, a bonding pattern is selected inwhich the longitudinal axis (longest dimension along a center line ofthe element) of one or more of the bonding elements is skewed relativeto the machine direction (“MD”) of the laminate. For example, one ormore of the bonding elements may be oriented from about 30° to about150°, in some embodiments from about 45° to about 135°, and in someembodiments, from about 60° to about 120° relative to the machinedirection of the laminate. In this manner, the bonding elements willpresent a relatively large surface to the laminate in a directionsubstantially perpendicular to that which the laminate moves.

The pattern of the bonding elements is generally selected so that thenonwoven facing has a total bond area of less than about 50% (asdetermined by conventional optical microscopic methods), and in someembodiments, less than about 30%. The bond density is also typicallygreater than about 50 bonds per square inch, and in some embodiments,from about 75 to about 500 pin bonds per square inch. One suitablebonding pattern for use in the present invention is known as an“S-weave” pattern and is described in U.S. Pat. No. 5,964,742 toMcCormack et al., which is incorporated herein in its entirety byreference thereto for all purposes. S-weave patterns typically have abonding element density of from about 50 to about 500 bonding elementsper square inch, and in some embodiments, from about 75 to about 150bonding elements per square inch. An example of a suitable “S-weave”pattern in shown in FIG. 7, which illustrates S-shaped bonding elements88 having a length dimension “L” and a width dimension “W.” Anothersuitable bonding pattern is known as the “rib-knit” pattern and isdescribed in U.S. Pat. No. 5,620,779 to Levy, et al., which isincorporated herein in its entirety by reference thereto for allpurposes. Rib-knit patterns typically have a bonding element density offrom about 150 to about 400 bonding elements per square inch, and insome embodiments, from about 200 to about 300 bonding elements persquare inch. An example of a suitable “rib-knit” pattern in shown inFIG. 8, which illustrates bonding elements 89 and bonding elements 91,which are oriented in a different direction, Yet another suitablepattern is the “wire weave” pattern, which has a bonding element densityof from about 200 to about 500 bonding elements per square inch, and insome embodiments, from about 250 to about 350 bonding elements persquare inch. An example of a suitable “wire-weave” pattern in shown inFIG. 9, which illustrates bonding elements 93 and bonding elements 95,which are oriented in a different direction. Still another suitablepattern is a “modified high density diamond” (MHDD) pattern. Other bondpatterns that may be used in the present invention are described in U.S.Pat. No. 3,855,046 to Hansen et al., U.S. Pat. No. 5,962,112 to Hayneset al., U.S. Pat. No. 6,093,665 to Sayovitz et al., U.S. Pat. No.0,375,844 to Edwards, et al., D390,708 to Brown, and D428,267 to Romanoet al., which are incorporated herein in their entirety by referencethereto for all purposes. Although the patterned rolls discussed aboveare generally utilized to bond the nonwoven facings of the presentinvention, such rolls, as briefly mentioned above, can also be used toform apertures in the nonwoven facings. In some embodiments, vacuumaperturing processes can also be used.

The selection of an appropriate bonding temperature (e.g., thetemperature of a heated roll) will help melt and/soften the polymer(s)of the nonwoven facing at regions adjacent to the bonding elements. Thesoftened polymer(s) may then flow and become displaced during bonding,such as by pressure exerted by the bonding elements. The displacedportions of the nonwoven facing can also fuse to other portions of thenonwoven facing, thereby reducing the fuzziness and reducing thefiber-pullout from the nonwoven facing typically experienced when bondedcarded webs and other meltblown and spunbond nonwoven webs are utilizedin a nonwoven facing. To achieve such bond formation on the nonwovenfacing, the bonding temperature, pressure, and nip speed may beselectively controlled. For example, one or more rolls may be adjustedto a surface temperature of from about 65° F. to about 300° F., in someembodiments from about 175° F. to about 250° F., and in someembodiments, from about 180° F. to about 240° F. Likewise, the pressureexerted by the bond rolls (“nip pressure”) during thermal bonding of thenonwoven facing may range from about 5 pound per square inch (psi) toabout 100 psi, such as from about 10 psi to about 65 psi, such as fromabout 15 psi to about 60 psi, such as from about 20 psi to about 50 psi.

Further, in some embodiments, the post-bond temperature can range fromabout 190° F. to about 210° F. and, the post-bond pressure can rangefrom about 10 psi to about 35 psi. In still other embodiments, thepost-bonding can be carried out at ambient temperature, such as fromabout 65° F. to about 75° F., to about 150° F., because of thesensitivity of the laminate to heat, such as when an olefin-basedelastomer such as VISTAMAXX™ is utilized, as such polymers may lose someof their elasticity when heated. Even using such low post-bondtemperatures and pressures, the present inventors have discovered that aspunbond or meltblown laminate can be formed. Of course, it should beunderstood that the residence time of the materials may influence theparticular bonding parameters employed. In addition, in someembodiments, the nip speed during bonding can range from about 1 footper minute (fpm) to about 60 fpm, such as from about 10 fpm to about 50fpm, such as from about 15 fpm to about 40 fpm. Meanwhile, in otherembodiments, the nip speed can range from about 100 fpm to about 3000fpm, such as from about 250 fpm to about 2500 fpm, such as from about500 fpm to about 2000 fpm.

Generally, as a result of the techniques discussed herein, spunbond ormeltblown nonwoven facings containing a polypropylene homopolymer with apolypropylene-based elastomer or a polyethylene homopolymer with apolyethylene-based elastomer. The elastomers can provide the nonwovenfacing with the desired level of softness, while at the same timeallowing for easier grooving of the nonwoven facing compared to if onlypolypropylene or polyethylene are utilized, which is a possibilityalthough such facings would be more loosely configured or fuzzy. Becausethe grooving of such nonwoven facings is easier to accomplish, there isless risk of damaging an underlying elastic film in laminates containingthe aforementioned nonwoven facings.

In reference to spunbond nonwoven facings particularly, incorporating anethylene-based elastomer such as INFUSE™ or a polypropylene-basedelastomer such as VERSIFY™ with a polyethylene or a polypropylenecreates a softer nonwoven facing that can be more easily grooved than anonwoven facing containing polyethylene as the only olefinic polymer.Likewise, incorporating a polypropylene-based elastomer such asVISTAMAXX™ with a polypropylene can create a softer nonwoven facing thatcan be more easily grooved compared to a nonwoven facing containingpolypropylene as the only olefinic polymer.

Further, in reference to meltblown nonwoven facings in particular,because meltblown facings generally include polymers having a lowermolecular weight than other facings and also are less tacky and notbonded when initially formed, which means that meltblown facings can begrooved more easily. Moreover, polypropylene meltblown facings can begrooved more easily than polyethylene meltblown facings becausepolypropylene is more brittle than polyethylene, which is softer. Inaddition, post-bonding of polyethylene-based meltblown facings can becarried out at lower temperatures and pressures because of their lowermolecular weights compared to spunbond facings and facings based onpolymers other than polyethylene.

However, regardless of whether the facings of the present invention arepolyethylene-based, polypropylene-based, spunbond, or meltblown, thefilm components, facing components, grooving conditions, and bondingconditions can be selected to achieve an elastic nonwoven laminate thathas the desired levels of softness and elasticity with reducedfuzziness, while at the same exhibiting enhanced hook engagement andresisting fiber pullout, such as when the elastic nonwoven laminates areused in absorbent article applications utilizing hook or tab fasteningmeans. For instance, when a tab or hook is attached to a laminate of thepresent invention that has been post bonded with smooth rolls, theelongation at failure (% elongation) of the tab or hook, whichcorresponds with hook disengagement, can range from about 50% to about200%, such as from about 75% to about 190%, such as from about 100% toabout 180%. Likewise, when a tab or hook is attached to a laminate ofthe present invention that has been post-bonded using a wire-weavepattern, the elongation at failure (% elongation) of the tab or hook canrange from about 50% to about 150%, such as from about 60% to about125%, such as from about 70% to about 100%.

Further, when a tab or hook is attached to a laminate of the presentinvention that has been post bonded with smooth rolls, the load atfailure can range from about 600 grams-force to about 2200 grams-force,such as from about 800 grams-force to about 2100 grams-force, such asfrom about 1000 grams-force to about 2000 grams-force. Meanwhile, when atab or hook is attached to a laminate of the present invention that hasbeen post-bonded using a wire-weave pattern, the load at failure canrange from about 400 grams-force to about 1200 grams-force, such as fromabout 500 grams-force to about 1100 grams-force, such as from about 600grams-force to about 1000 grams-force.

The components of the elastic nonwoven laminates of the presentinvention can also be selectively controlled to achieve the desiredtensile properties. For instance, elastic nonwoven laminates post-bondedwith smooth rolls can exhibit a percent elongation of greater than about200%, such as greater than about 400%, such as greater than about 800%.Further, elastic nonwoven laminates post-bonded using a wire-weavepattern can exhibit a percent elongation of greater than about 200%,such as from about 200% to about 1000%, such as from about 400% to about800%. In addition, elastic nonwoven laminates post-bonded using awire-weave pattern can exhibit a load at failure of greater than about3000 grams-force, such as greater than about 4000 grams-force, such asgreater than about 5000 grams-force. Meanwhile, elastic nonwovenlaminates post-bonded using a wire-weave pattern can exhibit a load atfailure of from about 1000 grams-force to about 4250 grams-force, suchas from about 1500 grams-force to about 4000 grams-force, such as fromabout 2000 grams-force to about 3750 grams-force.

Further, the laminates of the present invention can exhibit a load lossof less than about 60%, such as from about 10% to about 60%, such asfrom about 15% to about 55%, such as from about 30% to about 50%, whichis indicative that even with post-bonding, the laminates of the presentinvention maintain their elastic properties.

IV. Frangible Layer

Although the elastic nonwoven laminates discussed above have beendescribed as including an elastic film attached to one or more nonwovenfacings, it is also to be understood that the elastic nonwoven laminatesof the present invention can also include one or more frangible layerslocated outside the one or more facings layers or disposed between theone or more facing layers and the elastic film. Such frangible layersare described in U.S. patent application Ser. No. 13/720,194, filed onDec. 19, 2012, which is incorporated herein in its entirety by referencethereto for all purposes. Generally, the frangible layer can also begrooved in the manner described in reference to the nonwoven facings.The frangible layer can be used to add loftiness to the elastic nonwovenlaminates of the present invention or to achieve the desired aestheticsdepending on the particular application.

V. Articles

The elastic nonwoven laminate of the present invention may be used in awide variety of applications. As noted above, for example, the elasticnonwoven laminate may be used in an absorbent article. An “absorbentarticle” generally refers to any article capable of absorbing water orother fluids. Examples of some absorbent articles include, but are notlimited to, personal care absorbent articles, such as diapers, trainingpants, absorbent underpants, incontinence articles, feminine hygieneproducts (e.g., sanitary napkins), swim wear, baby wipes, and so forth;medical absorbent articles, such as garments, fenestration materials,underpads, bedpads, bandages, absorbent drapes, and medical wipes; foodservice wipers; clothing articles; and so forth. Materials and processessuitable for forming such absorbent articles are well known to thoseskilled in the art. Absorbent articles may include a substantiallyliquid-impermeable layer (e.g., outer cover), a liquid-permeable layer(e.g., bodyside liner, surge layer, etc.), and an absorbent core. In oneparticular embodiment, the elastic nonwoven laminate of the presentinvention may have a wide variety of other uses, such as in providing anelastic waist, leg cuff/gasketing, stretchable ear, side panel, outercover, or any other component in which elastic properties are desirable.

Referring to FIG. 10, for example, one embodiment of a disposable diaper250 is shown that generally defines a front waist section 255, a rearwaist section 260, and an intermediate section 265 that interconnectsthe front and rear waist sections. The front and rear waist sections 255and 260 include the general portions of the diaper which are constructedto extend substantially over the wearer's front and rear abdominalregions, respectively, during use. The intermediate section 265 of thediaper includes the general portion of the diaper that is constructed toextend through the wearer's crotch region between the legs. Thus, theintermediate section 265 is an area where repeated liquid surgestypically occur in the diaper.

The diaper 250 includes, without limitation, an outer cover, orbacksheet 270, a liquid permeable bodyside liner, or topsheet, 275positioned in facing relation with the backsheet 270, and an absorbentcore body, or liquid retention structure, 280, such as an absorbent pad,which is located between the backsheet 270 and the topsheet 275. Thebacksheet 270 defines a length, or longitudinal direction 286, and awidth, or lateral direction 285 which, in the illustrated embodiment,coincide with the length and width of the diaper 250. The liquidretention structure 280 generally has a length and width that are lessthan the length and width of the backsheet 270, respectively. Thus,marginal portions of the diaper 250, such as marginal sections of thebacksheet 270 may extend past the terminal edges of the liquid retentionstructure 280. In the illustrated embodiments, for example, thebacksheet 270 extends outwardly beyond the terminal marginal edges ofthe liquid retention structure 280 to form side margins and end marginsof the diaper 250. The topsheet 275 is generally coextensive with thebacksheet 270 but may optionally cover an area that is larger or smallerthan the area of the backsheet 270, as desired.

To provide improved fit and to help reduce leakage of body exudates fromthe diaper 250, the diaper side margins and end margins may beelasticized with suitable elastic members such as the elastic nonwovencomposite of the present invention, as further explained below. Forexample, as representatively illustrated in FIG. 10, the diaper 250 mayinclude leg/cuff gasketing 290 constructed to operably tension the sidemargins of the diaper 250 and closely fit around the legs of the wearerto reduce leakage and provide improved comfort and appearance.Waistbands 295 are employed that provide a resilient, comfortably closefit around the waist of the wearer. The elastic nonwoven laminate of thepresent invention is suitable for use as the leg/cuff gasketing 290and/or waistbands 295. Examples of such materials are laminates sheetsthat either comprise or are adhered to the backsheet, such that elasticconstrictive forces are imparted to the backsheet 270.

As is known, fastening means, such as hook and loop fasteners, may beemployed to secure the diaper 250 on a wearer. Alternatively, otherfastening means, such as buttons, pins, snaps, adhesive tape fasteners,cohesives, fabric-and-loop fasteners, or the like, may be employed. Inthe illustrated embodiment, the diaper 250 includes a pair of sidepanels 300 (or ears) to which the fasteners 302, indicated as the hookportion of a hook and loop fastener, are attached. Generally, the sidepanels 300 are attached to the side edges of the diaper in one of thewaist sections 255, 260 and extend laterally outward therefrom. The sidepanels 300 may contain the elastic material of the present invention.Examples of absorbent articles that include side panels and selectivelyconfigured fastener tabs are described in PCT Patent Application WO95/16425 to Roessler and U.S. Pat. No. 5,399,219 to Roessler et al.,U.S. Pat. No. 5,540,796 to Fries, and U.S. Pat. No. 5,595,618 to Fries,each of which is incorporated herein in its entirety by referencethereto for all purposes.

The diaper 250 may also include a surge management layer 305, locatedbetween the topsheet 275 and the liquid retention structure 280, torapidly accept fluid exudates and distribute the fluid exudates to theliquid retention structure 280 within the diaper 250. The diaper 250 mayfurther include a ventilation layer (not illustrated), also called aspacer, or spacer layer, located between the liquid retention structure280 and the backsheet 270 to insulate the backsheet 270 from the liquidretention structure 280 to reduce the dampness of the garment at theexterior surface of a breathable outer cover, or backsheet, 270.Examples of suitable surge management layers 305 are described in U.S.Pat. No. 5,486,166 to Bishop and U.S. Pat. No. 5,490,846 to Ellis.

As representatively illustrated in FIG. 10, the disposable diaper 250may also include a pair of containment flaps 310 which are configured toprovide a barrier to the lateral flow of body exudates and which can beformed from the elastic nonwoven laminates of the present invention. Thecontainment flaps 310 may be located along the laterally opposed sideedges of the diaper adjacent the side edges of the liquid retentionstructure 280. Each containment flap 310 typically defines an unattachededge that is configured to maintain an upright, perpendicularconfiguration in at least the intermediate section 265 of the diaper 250to form a seal against the wearer's body. The containment flaps 310 mayextend longitudinally along the entire length of the liquid retentionstructure 280 or may only extend partially along the length of theliquid retention structure. When the containment flaps 310 are shorterin length than the liquid retention structure 280, the containment flaps310 can be selectively positioned anywhere along the side edges of thediaper 250 in the intermediate section 265. Such containment flaps 310are generally well known to those skilled in the art. For example,suitable constructions and arrangements for containment flaps 310 aredescribed in U.S. Pat. No. 4,704,116 to Enloe.

The various regions and/or components of the diaper 250 may be assembledtogether using any known attachment mechanism, such as adhesive,ultrasonic, thermal bonds, etc. Suitable adhesives may include, forinstance, hot melt adhesives, pressure-sensitive adhesives, and soforth. When utilized, the adhesive may be applied as a uniform layer, apatterned layer, a sprayed pattern, or any of separate lines, swirls ordots. In the illustrated embodiment, for example, the topsheet 275 andbacksheet 270 may be assembled to each other and to the liquid retentionstructure 280 with lines of adhesive, such as a hot melt,pressure-sensitive adhesive. Similarly, other diaper components, such asthe leg/cuff gasketing 290, waistband 295, fastening members 302, andsurge layer 305 may be assembled into the article by employing theabove-identified attachment mechanisms.

Although various configurations of a diaper have been described above,it should be understood that other diaper and absorbent articleconfigurations are also included within the scope of the presentinvention. In addition, the present invention is by no means limited todiapers. In fact, any other absorbent article may be formed inaccordance with the present invention, including, but not limited to,other personal care absorbent articles, such as training pants,absorbent underpants, adult incontinence products, feminine hygieneproducts (e.g., sanitary napkins), swim wear, baby wipes, and so forth;medical absorbent articles, such as garments, fenestration materials,underpads, bandages, absorbent drapes, and medical wipes; food servicewipers; clothing articles; and so forth. Several examples of suchabsorbent articles are described in U.S. Pat. No. 5,649,916 to DiPalma,et al., U.S. Pat. No. 6,110,158 to Kielpikowski, and U.S. Pat. No.6,663,611 to Blaney, et al., which are incorporated herein in theirentirety by reference thereto for all purposes. Still other suitablearticles are described in U.S. Patent Application Publication No.2004/0060112 A1 to Fell, et al., as well as U.S. Pat. No. 4,886,512 toDamico et al., U.S. Pat. No. 5,558,659 to Sherrod, et al., U.S. Pat. No.6,511,465 to Freiburger, et al., and U.S. Pat. No. 6,888,044 to Fell, etal., all of which are incorporated herein in their entirety by referencethereto for all purposes. Of course, the elastic material is versatileand may also be incorporated into a wide variety of other types ofarticles. For example, the elastic material may be incorporated into amedical garment, such as gowns, caps, drapes, gloves, facemasks, etc.;industrial workwear garment, such as laboratory coats, coveralls, etc.;and so forth.

The present invention may be better understood with reference to thefollowing examples.

Test Methods

Tensile Testing:

Tensile measurements were conducted on various samples using an MTSSintech 1/S electro-mechanical tensile test frame equipped with MTS TestWorks data acquisition software. The cross-head speed used was 20inches/minute. Rectangular specimens having dimensions of 3 inches by 7inches were loaded in the jaws of the frame at a grip to grip distanceof 3 inches. The load-displacement data was collected at specified timeintervals. From knowledge of the load and displacement, the elongationat break (%) and corresponding load at failure (gram-force) wereobtained. The tests were conducted under ambient conditions.

Stress Relaxation Testing:

Stress relaxation testing was also carried out on an MTS Sintech 1/Selectro-mechanical tensile test frame. The test specimen was clampedbetween the jaws at a 3 inch grip to grip distance. The sample and thegrip fixtures were enclosed in an environmental chamber. The sample,after clamping, was equilibrated at 100° F. (about 37° C.) for 3minutes. The sample was then elongated to a final constant elongation of4.5 inches (50% elongation) at a cross-head displacement speed of 20inches/minute. The load required to maintain the 50% elongation as afunction of time was monitored. The data was acquired using MTS SintechTest Works data acquisition software.

From a plot of the log load versus log time, the slope was determinedand compared with an ideal elastic, which would have a slope of zero.The percentage loss of load at the end of the experiment was thendetermined. The load loss was obtained from a knowledge of the initialload and final load using the following equation: (Initial Load-FinalLoad)/(Initial Load)×100.

Hook Engagement Testing:

Hook engagement testing was also carried out on an MTS Sintech 1/Selectro-mechanical tensile test frame. A modified ASTM D3163 lap sheartest method was used to assess the shear force required for the pull-outof hooks off of various CD stretched laminates. A 1 inch wide by 5 inchlong hook (tab) sample was attached at a 1 inch depth perpendicular tothe stretch direction and in the middle of an elastic laminate that was3 inches wide by 5 inches long. The tab was placed in the upper gripwhile the other end of the elastic laminate was placed in the bottomgrip of the test frame. Each laminate sample was placed in the gripssuch that the center of the hook was 1.5 inches from the upper jaw. Fromknowledge of the load displacement data obtained using Test Works dataacquisition software at a data sampling rate of 10 Hertz, the percentelongation and load at failure were obtained.

Example 1

A film containing 90 wt. % of a core layer and two 5 wt. % skin layerswas extruded. The film components are shown below in Table 1.

TABLE 1 Wt. % 90 wt. % core layer SBS (KRATON ™ D1102) 39.5 SIBS(KRATON ™ D1171) 58 IRGANOX ™ 1010 Antioxidant 0.5 IRGAFOS ™ 168Stabilizer 0.5 TiO₂ Filler (SCC 11692) 1.5 Total 100 10 wt. % SkinLayers (2 Layers at 5 wt. % Each) LLDPE (DOWLEX ™ 2517) 59 LLDPE(DOWLEX ™ 2047) 39.5 TiO₂ Filler (SCC 11692) 1.5 Total 100

Example 2

A film containing 90 wt. % of a core layer and two 5 wt. % skin layerswas extruded. The film components are shown below in Table 2.

TABLE 2 Wt. % 90 wt. % Core Layer VISTAMAXX ™ 6102 98.5 TiO₂ Filler (SCC11692) 1.5 Total 100 10 wt. % Skin Layers (2 Layers at 5 wt. % Each)LLDPE (DOWLEX ™ 2517) 59 LLDPE (DOWLEX ™ 2047) 39.5 TiO₂ Filler (SCC11692) 1.5 Total 100

Example 3

A film containing 90 wt % of a core layer and two 5 wt. % skin layerswas extruded. The film had a basis weight of 60 gsm, and the componentsare shown below in Table 3.

TABLE 3 Wt. % 90 wt. % core layer VISTAMAXX ™ 6102 50 SEBS (KRATON ™ MD6937) 45 TiO₂ Filler (SCC 11692) 5 Total 100 10 wt. % Skin Layers (2Layers at 5 wt. % Each) LLDPE (DOWLEX ™ 2517) 59 LLDPE (DOWLEX ™ 2047)39.5 TiO₂ Filler (SCC 11692) 1.5 Total 100

Example 4

The ability to form a spunbond nonwoven facing was demonstrated. Thespunbond nonwoven facing had a basis weight of about 17 gsm and included69 wt % ASPUN™ 6850 A linear low density polyethylene (LLDPE) (DowChemical Company of Midland, Mich.), 29 wt. % of INFUSE™ 9817elastomeric copolymer of polyethylene (Dow Chemical Company of MidlandMich.), and 2 wt. % of titanium dioxide filler. The spunbond nonwovenfacing was bonded by passing the facing through two rolls, where oneroll was heated to a temperature of 250° F. (121° C.) and the other rollwas heated to a temperature of 230° F. (110° C.).

Example 5

The ability to form a spunbond nonwoven facing was demonstrated. Thespunbond nonwoven facing had a basis weight of about 17 gsm and included69 wt. % ASPUN™ 6850A linear low density polyethylene (LLDPE) (DowChemical Company of Midland, Mich.), 29 wt. % of INFUSE™ 9817elastomeric copolymer of polyethylene (Dow Chemical Company of MidlandMich.), and 2 wt. % of titanium dioxide filler. The spunbond nonwovenfacing was bonded by passing the facing through two rolls, where thepressure exerted by the rolls at the nip was 290 psi, and where bothrolls were heated to a temperature of 250° F. (121° C.).

Example 6

The ability to form a spunbond nonwoven facing was demonstrated. Thespunbond nonwoven facing had a basis weight of about 17 gsm and included69 wt. % DOWLEX™ 2517 linear low density polyethylene (LLDPE) (DowChemical Company of Midland, Mich.), 29 wt. % of INFUSE™ 9817elastomeric copolymer of polyethylene (Dow Chemical Company of MidlandMich.), and 2 wt. % of titanium dioxide filler. During bonding, thelaminate stuck to the bonder.

Example 7

The ability to form a spunbond nonwoven facing was demonstrated. Thespunbond nonwoven facing had a basis weight of about 17 gsm and included98 wt. % DOWLEX™ 2517 linear low density polyethylene (LLDPE) (DowChemical Company of Midland, Mich.) and 2 wt. % of titanium dioxidefiller. The nonwoven facing was poorly formed.

Example 8

The ability to form a spunbond nonwoven facing was demonstrated. Thespunbond nonwoven facing had a basis weight of about 15 gsm and included99 wt. % ASPUN™ 6850 A linear low density polyethylene (LLDPE) (DowChemical Company of Midland, Mich.) and 1 wt. % of titanium dioxidefiller. The spunbond nonwoven facing was bonded by passing the facingthrough two rolls, where the pressure exerted by the rolls at the nipwas 290 psi, and where both roils were heated to a temperature of 290°F. (143° C.).

Example 9

The ability to form a spunbond nonwoven facing was demonstrated. Thespunbond nonwoven facing had a basis weight of about 15 gsm and included99 wt. % DOW™ 61800 linear low density polyethylene (LLDPE) (DowChemical Company of Midland, Mich.) and 1 wt. % of titanium dioxidefiller.

Example 10

The ability to form a spunbond nonwoven facing was demonstrated. Thespunbond nonwoven facing had a basis weight of about 15 gsm and included89 wt. % DOW™ 61800 linear low density polyethylene (Dow ChemicalCompany of Midland, Mich.) 10 wt. % of INFUSE™ 9817 elastomericcopolymer of polyethylene (Dow Chemical Company of Midland Mich.), and 1wt. % of titanium dioxide filler. The spunbond nonwoven facing wasbonded by passing the facing through two rolls, where both rolls wereheated to a temperature of 270° F. (132° C.).

Example 11

The ability to form a spunbond nonwoven facing was demonstrated. Thespunbond nonwoven facing had a basis weight of about 15 gsm and included69 wt. % ASPUN™ 6850A linear low density polyethylene (Dow ChemicalCompany of Midland, Mich.), 30 wt. % of INFUSE™ 9817 elastomericcopolymer of polyethylene (Dow Chemical Company of Midland Mich.), and 1wt. % of titanium dioxide filler.

Example 12

The ability to form a spunbond nonwoven facing was demonstrated. Thespunbond nonwoven facing had a basis weight of about 15 gsm and included69 wt. % ASPUN™ 6850A linear low density polyethylene (Dow ChemicalCompany of Midland, Mich.), 30 wt. % of AFFINITY™ EG 8185polyethylene-based plastomer (Dow Chemical Company of Midland Mich.),and 1 wt. % of titanium dioxide filler.

Example 13

Laminates were formed containing the film of Example 1 disposed betweentwo nonwoven facings. The first nonwoven facing was a spunbond facingformed as described in Example 4 and having a basis weight of 17 gsm.The second nonwoven facing was a bonded carded web having a basis weightof 18 gsm and commercially available from Sandler AG of Germany.

To form the laminate, the film of Example 1 was extrusion cast onto achill roll at 76° F. The film was then e-beam crosslinked at 150 keV and150 kGy. The film was then laminated on one side to the spunbond facingof Example 4 and on the other side to the bonded carded web facing via apneumatic nip section via BOSTIK™ H2494 adhesive. The pneumatic nipsection included two rolls, where a top roll included an 80 Shore Ahardness silicone rubber and the bottom roll included a steel roll witha high release coating. A round hole die with 8 holes per inch was usedto apply the adhesive at 1.5 gsm add on per side. The resulting laminatewas then fed into a prototype groove roll unit with 8 grooves per inchand having a peak to peak distance of 0.125 inches and a depth of 0.272inches. The laminate was engaged at a depth range of 50% to 80% of thedepth of the grooves. The groove roll unit was heated using an oilheater, and grooves were formed in the laminate to decouple the facingsfrom the elastic film.

Next, the two facing sides of the laminate were post-bonded as describedbelow by feeding the laminate into a developmental bonding unit whichincluded either smooth anvil rolls or patterned rolls. The rolls wereheated by oil to the desired bonding temperature (200° F. or 230° F.)and the pneumatic nip pressure was varied from 15 psi to 50 psi.

After the laminates were formed, the laminates were post-bonded usingvarious temperatures and pressures. Tensile, hook engagement, and stressrelaxation testing as defined above were performed on each of thesamples 1-7 of Table 4, as shown in Tables 5-9 below.

TABLE 4 Posting-Bonding Conditions Bond Pressure Bond Temperature NipSpeed Sample (psi) (° F.) (fpm) Bond Pattern 1 15 200 20 Smooth Roll 225 200 20 Smooth Roll 3 40 200 20 Smooth Roll 4 20 200 20 Smooth Roll 530 230 30 Wire Weave 6 40 230 30 Wire Weave 7 40 230 30 Wire Weave

TABLE 5 Hook Engagement: Anvil on Anvil (Smooth) Spun Bond Side BondedCarded Web Side Bond Load at Load at Pressure/ Elonga- Failure Elonga-Failure Temperature tion (grams- tion (grams- Sample psi/° F. (%) force)(%) force) 8 15/200 130 1415 67 680 9 25/200 120 1470 49 565 10 30/200160 1945 60 630 11 40/200 80 1400 70 740 12 30/230 60 650 90 1270 1340/230 70 920 120 1610

As shown above in Samples 8-13, it is noted that a higher elongation atbreak and a higher load at failure can be achieved when post bonding wascarried out at lower temperatures and pressures on the spunbond side ofthe laminate, while the opposite was true for the bonded carded web sideof the laminate.

TABLE 6 Hook Engagement: Anvil on Wire Weave Spun Bond Side BondedCarded Web Side Bond Load at Load at Pressure/ Elonga- Failure Elonga-Failure Temperature tion (grams- tion (grams- Sample psi/° F. (%) force)(%) force) 14 20/200 75 890 110 1375 15 30/230 60 650 49 565 16 40/23070 920 120 610

As shown above in Samples 14-16, it is noted that a higher elongation atbreak could be achieved when post bonding was carried out at lowertemperatures and pressures on the spunbond side of the laminate, whilethe opposite was true for the bonded carded web side of the laminate.

TABLE 7 Tensile Properties: Anvil on Anvil Post-Bonded Laminates SpunBond Side Bond Pressure/ Load at Temperature Elongation Failure Samplepsi/° F. (%) (grams-force) 17 N/A (Control) >800* >4500* 1815/200 >800* >4500* 19 25/200 >800* >4500* 20 30/200 >800* >4500* 2140/200 800 4000 *Indicates sample reached the displacement limit of theMTS tensile test frame

As shown above in Samples 18-21, bonding the spunbond side of thelaminate at 200° F. and at pressures ranging from 15 psi to 40 psi withsmooth rollers did not negatively impact the tensile properties of thelaminate as compared to the unbonded control Sample 20, and elongationswell over 200% were achieved.

TABLE 8 Tensile Properties: Anvil on Wire Weave Post-Bonded LaminatesSpun Bond Side Bond Pressure/ Load at Temperature Elongation FailureSample psi/° F. (%) (grams-force) 22 20/230 610 2750 23 30/230 690 370024 40/230 640 3200

As shown above in Samples 22-24, bonding the spunbond side of thelaminate at 230° F. and at pressures ranging from 20 psi to 40 psi withsmooth rollers did slightly decrease the tensile properties of thelaminate as compared to the unbonded control Sample 20, althoughelongations well over 200% were achieved. The decrease in the tensileproperties is the result of apertures formed in the facings duringpost-bonding that were not present when smooth rolls were used forpost-bonding.

TABLE 9 Stress Relaxation Testing: Anvil on Anvil Laminates Spun BondSide Bond Pressure/ Temperature Load Loss Sample psi/° F. Slope (%) 25N/A (Control) 0.09 48 26 15/200 0.08 49 27 25/200 0.07 43 28 30/200 0.0746 29 40/230 0.09 52

A lower slope and load loss percent during stress relaxation testing isgenerally indicative of a material that has better elastic behavior. Asshown above, Samples 26-28, which were bonded at 200° F. and atpressures ranging from 15 psi to 30 psi, maintained or had betterelastic behavior than the control sample which was not post-bonded.

In summary, the laminates of the present invention exhibited elasticcharacteristics, while also maintaining good mechanical properties andexhibiting good hook or tab engagement.

Example 14

Next, the ability to form a laminate including the film as formed inExample 2 disposed between two 100% spunbond facings was demonstrated.FIG. 11 is a photograph of the film after it has been post-bonded with apatterned roll and stretched to 70% elongation. Meanwhile, FIG. 12 is aphotograph of the laminate without any post-bonding and stretched to 70%elongation. A comparison of FIGS. 11 and 12 shows that a bond pattern isvisible on the laminate of FIG. 11, which is not visible on FIG. 12.

While the invention has been described in detail with respect to thespecific embodiments thereof, it will be appreciated that those skilledin the art, upon attaining an understanding of the foregoing, mayreadily conceive of alterations to, variations of, and equivalents tothese embodiments. Accordingly, the scope of the present inventionshould be assessed as that of the appended claims and any equivalentsthereto.

What is claimed is:
 1. An elastic nonwoven laminate having a machinedirection and a cross-machine direction, the elastic nonwoven laminatecomprising an unstretched elastic film disposed between a first nonwovenfacing and a second nonwoven facing, wherein the first nonwoven facingcomprises a first polyolefin, wherein the first nonwoven facing ismeltblown or spunbond, wherein the first nonwoven facing and the secondnonwoven facing are simultaneously grooved in the machine direction orcross-machine direction to decouple the first nonwoven facing and thesecond nonwoven facing from the elastic film, wherein grooves in thefirst nonwoven facing correspond with grooves in the second nonwovenfacing, and wherein an outer surface of each of the first nonwovenfacing and the second nonwoven facing is post-bonded after the firstnonwoven facing and the second nonwoven facing are simultaneouslygrooved such that from about 1 groove per inch to about 12 grooves perinch are present on the outer surface of each of the first nonwovenfacing and the second nonwoven facing after post-bonding, wherein theouter surface of each of the first nonwoven facing and the secondnonwoven facing are bonded in a pattern comprising bonded areas, whereinbonded areas of the first nonwoven facing and the second nonwoven facingare non-fibrous, wherein the elastic nonwoven laminate has a percentelongation of at least about 200% in the cross-machine direction,wherein the first nonwoven facing and the second nonwoven facing eachexhibit reduced fiber pull-out compared to a nonwoven facing that is notpost-bonded.
 2. The elastic nonwoven laminate of claim 1, wherein thefirst polyolefin comprises polyethylene, polypropylene, or a combinationthereof.
 3. The elastic nonwoven laminate of claim 1, wherein the firstnonwoven facing further comprises a second polyolefin, wherein thesecond polyolefin comprises an elastomeric semi-crystalline polyolefin.4. The elastic nonwoven laminate of claim 3 wherein the elastomericsemi-crystalline polyolefin is an ethylene/α-olefin copolymer,propylene/α-olefin copolymer, or a combination thereof.
 5. The elasticnonwoven laminate of claim 3, wherein the first polyolefin is present inan amount ranging from about 50 wt. % to about 99 wt. % and the secondpolyolefin is present in an amount ranging from about 0.5 wt. % to about60 wt %, based on the total weight of the first nonwoven facing.
 6. Theelastic nonwoven laminate of claim 1, wherein the elastic film comprisesa core layer disposed between two skin layers, wherein the core layer isan elastic layer comprising a styrenic block copolymer, anethylene/α-olefin copolymer, a propylene/α-olefin copolymer, or acombination thereof.
 7. The elastic nonwoven laminate of claim 1,wherein the elastic film comprises a core layer disposed between twoskin layers, wherein the core layer is a strength layer, and wherein thetwo skin layers are elastic layers.
 8. The elastic nonwoven laminate ofclaim 1, further comprising a frangible layer.
 9. The elastic nonwovenlaminate of claim 1, wherein the elastic nonwoven laminate has a percentelongation ranging from 610% to about 1000% in the cross-machinedirection.
 10. The elastic nonwoven laminate of claim 1, whereinpost-bonding occurs at a temperature ranging from about 175° F. to about250° F.